-
Notifications
You must be signed in to change notification settings - Fork 791
Expand file tree
/
Copy pathOverview.html
More file actions
executable file
·1547 lines (1274 loc) · 103 KB
/
Overview.html
File metadata and controls
executable file
·1547 lines (1274 loc) · 103 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html><html lang=en><head>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
<title>CSS Lists and Counters Module Level 3</title>
<link href=../default.css rel=stylesheet type=text/css>
<link href=../csslogo.ico rel="shortcut icon" type=image/x-icon>
<style>
body {
background: url("https://www.w3.org/StyleSheets/TR/logo-ED") top left no-repeat white;
background-attachment: fixed;
color: black;
font-family: sans-serif;
margin: 0 auto;
max-width: 50em;
padding: 2em 1em 2em 70px;
}
:link { color: #00C; background: transparent }
:visited { color: #609; background: transparent }
a[href]:active { color: #C00; background: transparent }
a[href]:hover { background: #ffa }
a[href] img { border-style: none }
h1, h2, h3, h4, h5, h6 { text-align: left }
h1, h2, h3 { color: #005A9C; }
h1 { font: 170% sans-serif }
h2 { font: 140% sans-serif }
h3 { font: 120% sans-serif }
h4 { font: bold 100% sans-serif }
h5 { font: italic 100% sans-serif }
h6 { font: small-caps 100% sans-serif }
.hide { display: none }
div.head { margin-bottom: 1em }
div.head h1 { margin-top: 2em; clear: both }
div.head table { margin-left: 2em; margin-top: 2em }
p.copyright { font-size: small }
p.copyright small { font-size: small }
pre { margin-left: 2em }
dt { font-weight: bold }
ul.toc, ol.toc {
list-style: none;
}
</style>
</head>
<body class=h-entry>
<style scoped>
#counter-inheritance-example b.foo { color: hsl(0, 80%, 40%); }
#counter-inheritance-example b.bar { color: hsl(120, 80%, 30%); }
#counter-inheritance-example b.baz { color: hsl(240, 80%, 50%); }
</style>
<div class=head>
<p data-fill-with=logo><a class=logo href=http://www.w3.org/>
<img alt=W3C height=48 src=http://www.w3.org/Icons/w3c_home width=72>
</a>
</p>
<h1 class="p-name no-ref" id=title>CSS Lists and Counters Module Level 3</h1>
<h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>Editor’s Draft,
<span class=dt-updated><span class=value-title title=20140122>22 January 2014</span></span></span></h2>
<div data-fill-with=spec-metadata><dl><dt>This version:<dd><a class=u-url href=http://dev.w3.org/csswg/css3-lists/>http://dev.w3.org/csswg/css3-lists/</a><dt>Latest version:<dd><a href=http://www.w3.org/TR/css3-lists/>http://www.w3.org/TR/css3-lists/</a><dt>Editor’s Draft:<dd><a href=http://dev.w3.org/csswg/css3-lists/>http://dev.w3.org/csswg/css3-lists/</a><dt>Previous Versions:<dd><a href=http://www.w3.org/TR/2011/WD-css3-lists-20110524/ rel=previous>http://www.w3.org/TR/2011/WD-css3-lists-20110524/</a>
<dt>Feedback:</dt>
<dd><a href="mailto:www-style@w3.org?subject=%5Bcss-lists%5D%20feedback">www-style@w3.org</a>
with subject line
“<kbd>[css-lists] <var>… message topic …</var></kbd>”(<a href=http://lists.w3.org/Archives/Public/www-style/ rel=discussion>archives</a>)<dt>Test Suite:<dd>None Yet<dt>Editors:
<dd class="p-author h-card vcard"><a class="p-name fn u-url url" href=http://xanthir.com/contact/>Tab Atkins</a> (<span class="p-org org">Google</span>)<dt>Former Editors:
<dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:ian@hixie.ch>Ian Hickson</a> (<span class="p-org org">Google</span>)<dd class="p-author h-card vcard"><a class="p-name fn u-email email" href=mailto:tantekc@microsoft.com>Tantek Çelı̇k</a> (<span class="p-org org">Formerly of Microsoft</span>)<dt>Contributors:<dd>Simon Montagu, AOL-TW/Netscape, <a href=mailto:smontagu@netscape.com>smontagu@netscape.com</a><dd>Daniel Yacob, <a href=mailto:yacob@geez.org>yacob@geez.org</a><dd>Christopher Hoess, <a href=mailto:choess@stwing.upenn.edu>choess@stwing.upenn.edu</a><dd>Daniel Glazman, AOL-TW/Netscape, <a href=mailto:glazman@netscape.com>glazman@netscape.com</a><dt>Issue Tracking:<dd><a href="https://www.w3.org/Bugs/Public/buglist.cgi?product=CSS&component=Lists%20and%20Counters&resolution=---">Bugzilla</a></dl></div>
<div data-fill-with=warning></div>
<p class=copyright data-fill-with=copyright><a href=http://www.w3.org/Consortium/Legal/ipr-notice#Copyright>Copyright</a> © 2013 <a href=http://www.w3.org/><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href=http://www.csail.mit.edu/><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href=http://www.ercim.eu/><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href=http://www.keio.ac.jp/>Keio</a>, <a href=http://ev.buaa.edu.cn/>Beihang</a>), All Rights Reserved. W3C <a href=http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer>liability</a>, <a href=http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks>trademark</a> and <a href=http://www.w3.org/Consortium/Legal/copyright-documents>document use</a> rules apply.
</p>
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc no-ref heading settled heading" id=abstract><span class=content>Abstract</span></h2>
<p class=p-summary data-fill-with=abstract>This draft contains the features of CSS level 3 relating to list styling. It includes and extends the functionality of CSS level 2 <a data-biblio-type=normative data-link-type=biblio href=#css21 title=css21>[CSS21]</a>. The main extensions compared to level 2 are a pseudo-element representing the list marker, and a method for authors to define their own list-styles.
<a href=http://www.w3.org/TR/CSS/>CSS</a> is a language for describing the rendering of structured documents
(such as HTML and XML)
on screen, on paper, in speech, etc.</p>
<h2 class="no-num no-toc no-ref heading settled heading" id=status><span class=content>Status of this document</span></h2>
<div data-fill-with=status><p>
This is a public copy of the editors’ draft.
It is provided for discussion only and may change at any moment.
Its publication here does not imply endorsement of its contents by W3C.
Don’t cite this document other than as work in progress.
<p>
The (<a href=http://lists.w3.org/Archives/Public/www-style/>archived</a>) public mailing list
<a href="mailto:www-style@w3.org?Subject=%5Bcss-lists%5D%20PUT%20SUBJECT%20HERE">www-style@w3.org</a>
(see <a href=http://www.w3.org/Mail/Request>instructions</a>)
is preferred for discussion of this specification.
When sending e-mail,
please put the text “css-lists” in the subject,
preferably like this:
“[css-lists] <em>…summary of comment…</em>”
<p>
This document was produced by the <a href=http://www.w3.org/Style/CSS/members>CSS Working Group</a>
(part of the <a href=http://www.w3.org/Style/>Style Activity</a>).
<p>
This document was produced by a group operating under
the <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/>5 February 2004 W3C Patent Policy</a>.
W3C maintains a <a href=http://www.w3.org/2004/01/pp-impl/32061/status rel=disclosure>public list of any patent disclosures</a>
made in connection with the deliverables of the group;
that page also includes instructions for disclosing a patent.
An individual who has actual knowledge of a patent which the individual believes contains <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential>Essential Claim(s)</a>
must disclose the information in accordance with <a href=http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure>section 6 of the W3C Patent Policy</a>.</div>
<div data-fill-with=at-risk></div>
<h2 class="no-num no-toc no-ref heading settled heading" id=contents><span class=content>Table of contents</span></h2>
<div data-fill-with=table-of-contents><ul class=toc><li><a href=#intro><span class=secno>1</span>
Introduction</a><li><a href=#declaring-a-list-item><span class=secno>2</span>
Declaring a List Item</a><li><a href=#marker-content><span class=secno>3</span>
Default Marker Contents: The <span class=property data-link-type=propdesc title=list-style-image>list-style-image</span> and <span class=property data-link-type=propdesc title=list-style-type>list-style-type</span> properties</a><li><a href=#list-style-position-property><span class=secno>4</span>
Marker Position: The <span class=property data-link-type=propdesc title=list-style-position>list-style-position</span> property</a><li><a href=#list-style-property><span class=secno>5</span>
The <span class=property data-link-type=propdesc title=list-style>list-style</span> shorthand property</a><li><a href=#marker-pseudo-element><span class=secno>6</span>
Markers: The <span class=css data-link-type=maybe title=::marker>::marker</span> pseudo-element</a><ul class=toc><li><a href=#content-property><span class=secno>6.1</span>
Generating the value of the <span class=property data-link-type=propdesc title=content>content</span> property</a></ul><li><a href=#positioning-markers><span class=secno>7</span>
Positioning Markers</a><ul class=toc><li><a href=#position-marker><span class=secno>7.1</span>
The <span class=css data-link-type=maybe title=marker>marker</span> value for <span class=property data-link-type=propdesc title=position>position</span></a><li><a href=#marker-side><span class=secno>7.2</span>
The <span class=property data-link-type=propdesc title=marker-side>marker-side</span> property</a></ul><li><a href=#counter><span class=secno>8</span>
Automatic Numbering With Counters</a><ul class=toc><li><a href=#counter-properties><span class=secno>8.1</span>
Manipulating Counters: the <span class=property data-link-type=propdesc title=counter-increment>counter-increment</span>, <span class=property data-link-type=propdesc title=counter-set>counter-set</span> and <span class=property data-link-type=propdesc title=counter-reset>counter-reset</span> properties</a><li><a href=#creating-counters><span class=secno>8.2</span>
Creating and Inheriting Counters</a><li><a href=#nested-counters><span class=secno>8.3</span>
Nested Counters</a><li><a href=#counters-without-boxes><span class=secno>8.4</span>
Counters in elements that do not generate boxes</a></ul><li><a href=#counter-functions><span class=secno>9</span>
Printing Counters: the <span class=css data-link-type=maybe title=counter()>counter()</span> and <span class=css data-link-type=maybe title=counters()>counters()</span> functions</a><li><a href=#ua-stylesheet><span class=secno>10</span>
Sample style sheet for HTML</a><li><a href=#acknowledgments><span class=secno></span>
Acknowledgments</a><li><a href=#changes><span class=secno></span>
Changes From CSS2.1</a><li><a href=#conformance><span class=secno></span>
Conformance</a><ul class=toc><li><a href=#conventions><span class=secno></span>
Document conventions</a><li><a href=#conformance-classes><span class=secno></span>
Conformance classes</a><li><a href=#partial><span class=secno></span>
Partial implementations</a><li><a href=#experimental><span class=secno></span>
Experimental implementations</a><li><a href=#testing><span class=secno></span>
Non-experimental implementations</a></ul><li><a href=#references><span class=secno></span>
References</a><ul class=toc><li><a href=#normative><span class=secno></span>
Normative References</a><li><a href=#informative><span class=secno></span>
Informative References</a></ul><li><a href=#index><span class=secno></span>
Index</a><li><a href=#property-index><span class=secno></span>
Property index</a><li><a href=#issues-index><span class=secno></span>Issues Index</a></ul></div>
<h2 class="heading settled heading" data-level=1 id=intro><span class=secno>1 </span><span class=content>
Introduction</span><a class=self-link href=#intro></a></h2>
<p> This specification defines the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element,
the <a class=css data-link-type=maybe href=#valuedef-list-item title=list-item>list-item</a> and <a class=css data-link-type=maybe href=#valuedef-inline-list-item title=inline-list-item>inline-list-item</a> <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display</a> values that generate markers,
and several properties controlling the placement and styling of markers.
<p> It also defines <a data-link-type=dfn href=#counter0 title=counters>counters</a>,
which are special numerical objects
often used to generate the default contents of markers.
<div class=example>
For instance, the following example illustrates how markers may be used to add parentheses around each numbered list item:
<pre> <style>
li::marker { content: "(" counter(list-item, lower-roman) ")"; }
li { display: list-item; }
</style>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
</pre>
<p> It should produce something like this:
<pre> (i) This is the first item.
(ii) This is the second item.
(iii) This is the third item.
</pre>
<p class=note> Note: Note that this example is far more verbose than is usually needed in HTML,
as the UA default style sheet takes care of most of the necessary styling.
</div>
<p> With descendant selectors and child selectors,
it’s possible to specify different marker types depending on the depth of embedded lists.
<p class=issue id=issue-6c0d2c9e><a class=self-link href=#issue-6c0d2c9e></a>
A future release of this module will probably include ways to render tree lists.
<h2 class="heading settled heading" data-level=2 id=declaring-a-list-item><span class=secno>2 </span><span class=content>
Declaring a List Item</span><a class=self-link href=#declaring-a-list-item></a></h2>
<p> A <dfn data-dfn-type=dfn data-export="" id=list-item>list item<a class=self-link href=#list-item></a></dfn> is any element with its <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display</a> property set to <a class=css data-link-type=maybe href=#valuedef-list-item title=list-item>list-item</a> or <a class=css data-link-type=maybe href=#valuedef-inline-list-item title=inline-list-item>inline-list-item</a>.
<a data-link-type=dfn href=#list-item title="list items">List items</a> generate <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-elements;
no other elements do.
<p> Additionally, <a data-link-type=dfn href=#list-item title="list items">list items</a> automatically increment the special <a class=css data-link-type=maybe href=#valuedef-list-item title=list-item>list-item</a> <a data-link-type=dfn href=#counter0 title=counter>counter</a>.
Unless the <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a> property manually specifies a different increment for the <a class=css data-link-type=maybe href=#valuedef-list-item title=list-item>list-item</a> <a data-link-type=dfn href=#counter0 title=counter>counter</a>,
it must be incremented by 1 on every <a data-link-type=dfn href=#list-item title="list item">list item</a>,
at the same time that <a data-link-type=dfn href=#counter0 title=counters>counters</a> are normally incremented.
(This has no effect on the values of the <a class=property data-link-type=propdesc title=counter-*>counter-*</a> properties.)
<table class="definition propdef partial"><tr><th>Name:<td><a class=css-code data-link-type=property href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display</a><tr><th>New values:<td>inline-list-item</table>
<p> The <dfn class=css-code data-dfn-for=display data-dfn-type=value data-export="" id=valuedef-inline-list-item>inline-list-item<a class=self-link href=#valuedef-inline-list-item></a></dfn> display value makes the element a <a data-link-type=dfn href=#list-item title="list item">list item</a>,
with the effects described above.
Additionally, the <a class=css data-link-type=maybe href=#list-style-position-outside title=outside>outside</a> value of <a class=property data-link-type=propdesc href=#propdef-list-style-position title=list-style-position>list-style-position</a>
computes to <a class=css data-link-type=maybe href=#valuedef-inside title=inside>inside</a> on this element.
Otherwise, this display value is treated identically to <span class=css data-link-type=maybe title=inline>inline</span>.
<p class=note> Note: This display value is silly,
and only necessary because we haven’t yet defined <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display</a> to be split into subproperties.
When that happens,
"being a list item" will just be a property value that can apply to block, inline, and other elements.
<h2 class="heading settled heading" data-level=3 id=marker-content><span class=secno>3 </span><span class=content>
Default Marker Contents: The <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> and <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> properties</span><a class=self-link href=#marker-content></a></h2>
<p> The contents of a <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element can be generated automatically,
rather than being specified explicitly with <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a>.
The <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> and <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> properties control how these contents are generated.
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-list-style-image>list-style-image<a class=self-link href=#propdef-list-style-image></a></dfn><tr><th>Value:<td><a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-images-3/#image-type title="<image>"><image></a> | none<tr><th>Initial:<td>none<tr><th>Applies to:<td><a data-link-type=dfn href=#list-item title="list items">list items</a><tr><th>Inherited:<td>yes<tr><th>Media:<td>visual<tr><th>Computed value:<td>computed value fo the <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-images-3/#image-type title="<image>"><image></a>, or <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a><tr><th>Percentages:<td>n/a</table>
<p> The <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> property specifies an image that will be used as the list marker’s <a data-link-type=dfn href=#default-contents title="default contents">default contents</a>.
The values are defined as follows:
<dl data-dfn-for=list-style-image data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=list-style-image data-dfn-type=value data-export="" id=valuedef-image><image><a class=self-link href=#valuedef-image></a></dfn>
<dd>
If the <code><image></code> is not an <a href=http://www.w3.org/TR/css3-images/#invalid-image>invalid image</a>,
the image is the <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> of the list item’s marker.
Otherwise, the <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> are given by <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> instead.
<dt><dfn class=css-code data-dfn-for=list-style-image data-dfn-type=value data-export="" id=valuedef-none0>none<a class=self-link href=#valuedef-none0></a></dfn>
<dd>
The <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> of the of the list item’s marker are given by <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> instead.
</dl>
<div class=example>
The following example sets the marker at the beginning of each list item to
be the image "ellipse.png".
<pre>li { list-style-image: url("http://www.example.com/ellipse.png") }</pre> </div>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-list-style-type>list-style-type<a class=self-link href=#propdef-list-style-type></a></dfn><tr><th>Value:<td><a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#string-value title="<string>"><string></a> | <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-counter-styles-3/#typedef-counter-style title="<counter-style>"><counter-style></a> | none<tr><th>Initial:<td>disc<tr><th>Applies to:<td><a data-link-type=dfn href=#list-item title="list items">list items</a><tr><th>Inherited:<td>yes<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a</table>
<p> When the value of <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> is <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>
or an <a href=http://www.w3.org/TR/css3-images/#invalid-image>invalid image</a>,
the <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> property is used to construct the default contents of a list item’s marker;
otherwise, <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> is ignored.
The values are defined as follows:
<dl data-dfn-for=list-style-type data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=list-style-type data-dfn-type=value data-export="" id=valuedef-string><string><a class=self-link href=#valuedef-string></a></dfn>
<dd>
The <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#string-value title="<string>"><string></a> is used as the list item’s marker’s <a data-link-type=dfn href=#default-contents title="default contents">default contents</a>.
<dt><dfn class=css-code data-dfn-for=list-style-type data-dfn-type=value data-export="" id=valuedef-counter-style><counter-style><a class=self-link href=#valuedef-counter-style></a></dfn>
<dd>
If there is a counter style defined matching the <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-counter-styles-3/#typedef-counter-style title="<counter-style>"><counter-style></a>,
the list item’s marker’s <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> are that counter style. <a data-biblio-type=informative data-link-type=biblio href=#css-counter-styles-3 title=css-counter-styles-3>[CSS-COUNTER-STYLES-3]</a>
Otherwise, the list item’s marker’s <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> are <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>.
<dt><dfn class=css-code data-dfn-for=list-style-type data-dfn-type=value data-export="" id=valuedef-none1>none<a class=self-link href=#valuedef-none1></a></dfn>
<dd>
The list item’s marker’s <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> are <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>.
</dl>
<div class=example>
<p>The following examples illustrate how to set markers to various values:
<pre> ul { list-style-type: "★"; }
/* Sets the marker to a "star" character */
p.note {
display: list-item;
list-style-type: "Note: ";
list-style-position: inside;
}
/* Gives note paragraphs a marker consisting of the string "Note: " */
ol { list-style-type: upper-roman; }
/* Sets all ordered lists to use the upper-roman counter-style
(defined in the Counter Styles specification [[CSS-COUNTER-STYLES]]) */
ul { list-style-type: symbols(repeating '○' '●'); }
/* Sets all unordered list items to alternate between empty and
filled circles for their markers. */
ul { list-style-type: none; }
/* Suppresses the marker entirely, unless list-style-image is specified
with a valid image, or the marker’s contents are set explicitly via
the 'content' property. */
</pre> </div>
<h2 class="heading settled heading" data-level=4 id=list-style-position-property><span class=secno>4 </span><span class=content>
Marker Position: The <a class=property data-link-type=propdesc href=#propdef-list-style-position title=list-style-position>list-style-position</a> property</span><a class=self-link href=#list-style-position-property></a></h2>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-list-style-position>list-style-position<a class=self-link href=#propdef-list-style-position></a></dfn><tr><th>Value:<td>inside | outside<tr><th>Initial:<td>outside<tr><th>Applies to:<td><a data-link-type=dfn href=#list-item title="list items">list items</a><tr><th>Inherited:<td>yes<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value (but see prose)<tr><th>Percentages:<td>n/a</table>
<p> This property helps control the position of the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element in the <a data-link-type=dfn href=#list-item title="list item">list item</a>.
The values are defined as follows:
<dl data-dfn-for=list-style-position data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=list-style-position data-dfn-type=value data-export="" id=valuedef-inside>inside<a class=self-link href=#valuedef-inside></a></dfn>
<dd>
The <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element is an inline element placed immediately before where the <span class=css data-link-type=maybe title=::before>::before</span> pseudo-element would be placed in the <a data-link-type=dfn href=#list-item title="list item">list item</a>.
<dt><dfn class=css-code data-dfn-for=list-style-position data-dfn-type=value data-export="" id=list-style-position-outside>outside<a class=self-link href=#list-style-position-outside></a></dfn>
<dd>
As <a class=css data-link-type=maybe href=#valuedef-inside title=inside>inside</a>, plus the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a> property on the marker computes to <a class=css data-link-type=maybe href=#valuedef-marker title=marker>marker</a>.
Additionally, the base directionality of the marker
(used as an input to the bidi resolution algorithm)
must be taken from the marker’s <a data-link-type=dfn href=#marker-positioning-reference-element title="marker positioning reference element">marker positioning reference element</a>.
<p> If the <a data-link-type=dfn href=#list-item title="list item">list item</a> is <a class=css data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display: inline-list-item</a>,
this value computes to <a class=css data-link-type=maybe href=#valuedef-inside title=inside>inside</a>.
</dl>
<p class=note> Note: Note that a marker is only generated
if the used value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property for the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element is not <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>.
<div class=example>
For example:
<pre> <style>
ul.compact { list-style: inside; }
ul { list-style: outside; }
</style>
<ul class=compact>
<li>first "inside" list item comes first</li>
<li>second "inside" list item comes first</li>
</ul>
<hr>
<ul>
<li>first "outside" list item comes first</li>
<li>second "outside" list item comes first</li>
</ul>
</pre>
<p> The above example may be formatted as:
<pre> * first "inside" list
item comes first
* second "inside" list
item comes second
========================
* first "outside" list
item comes first
* second "outside" list
item comes second</pre> </div>
<h2 class="heading settled heading" data-level=5 id=list-style-property><span class=secno>5 </span><span class=content>
The <a class=property data-link-type=propdesc href=#propdef-list-style title=list-style>list-style</a> shorthand property</span><a class=self-link href=#list-style-property></a></h2>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-list-style>list-style<a class=self-link href=#propdef-list-style></a></dfn><tr><th>Value:<td><a class=production data-link-type=propdesc href=#propdef-list-style-type title=list-style-type><‘list-style-type’></a> || <a class=production data-link-type=propdesc href=#propdef-list-style-position title=list-style-position><‘list-style-position’></a> || <a class=production data-link-type=propdesc href=#propdef-list-style-image title=list-style-image><‘list-style-image’></a><tr><th>Initial:<td>see individual properties<tr><th>Applies to:<td><a data-link-type=dfn href=#list-item title="list items">list items</a><tr><th>Inherited:<td>see individual properties<tr><th>Media:<td>visual<tr><th>Computed value:<td>see individual properties<tr><th>Percentages:<td>see individual properties</table>
<p> The <a class=property data-link-type=propdesc href=#propdef-list-style title=list-style>list-style</a> property is a shorthand notation
for setting the three properties <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a>, <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a>, and <a class=property data-link-type=propdesc href=#propdef-list-style-position title=list-style-position>list-style-position</a>
at the same place in the style sheet.
<div class=example>
For example:
<pre> UL { list-style: upper-roman inside } /* Any UL */
UL UL { list-style: circle outside } /* Any UL child of a UL */
</pre> </div>
<p> Using a value of <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a> in the shorthand is potentially ambiguous,
as <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a> is a valid value for both <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> and <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a>.
To resolve this ambiguity,
a value of <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a> in the shorthand must be applied to whichever of the two properties aren’t otherwise set by the shorthand.
<div class=example>
<pre> list-style: none disc;
/* Sets the image to "none" and the type to "disc". */
list-style: none url(bullet.png);
/* Sets the image to "url(bullet.png)" and the type to "none". */
list-style: none;
/* Sets both image and type to "none". */
list-style: none disc url(bullet.png);
/* Syntax error */
</pre> </div>
<div class=example>
Although authors may specify <a class=property data-link-type=propdesc href=#propdef-list-style title=list-style>list-style</a> information directly on list item elements
(e.g., <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-li-element title=li>li</a> in HTML),
they should do so with care.
Consider the following rules:
<pre> ol.alpha li { list-style: lower-alpha; }
ul li { list-style: disc; }
</pre>
<p> The above won’t work as expected.
If you nest a <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-ul-element title=ul>ul</a> into an <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-ol-element title=ol>ol class=alpha</a>,
the first rule’s specificity will make the <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-ul-element title=ul>ul</a>’s list items use the lower-alpha style.
<pre> ol.alpha > li { list-style: lower-alpha; }
ul > li { list-style: disc; }
</pre>
<p> These work as intended.
<pre> ol.alpha { list-style: lower-alpha; }
ul { list-style: disc; }
</pre>
<p> These are even better,
since inheritance will transfer the <a class=property data-link-type=propdesc href=#propdef-list-style title=list-style>list-style</a> value to the list items.
</div>
<h2 class="heading settled heading" data-level=6 id=marker-pseudo-element><span class=secno>6 </span><span class=content>
Markers: The <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element</span><a class=self-link href=#marker-pseudo-element></a></h2>
<p> This specification defines a new type of pseudo-element,
the <dfn class=css-code data-dfn-type=selector data-export="" id=selectordef-marker>::marker<a class=self-link href=#selectordef-marker></a></dfn> pseudo-element,
which is generated by <a data-link-type=dfn href=#list-item title="list items">list items</a> to represent the item’s marker
(the bullet or number identifying each item).
<p> Like <span class=css data-link-type=maybe title=::before>::before</span> and <span class=css data-link-type=maybe title=::after>::after</span>,
the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element can be styled with the full range of CSS properties and values,
exactly like a real element.
Markers are placed at the beginning of their superior parent’s content,
before the <span class=css data-link-type=maybe title=::before>::before</span> pseudo-element (if it exists).
<a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-elements are inline by default,
though certain values for <a class=property data-link-type=propdesc href=#propdef-list-style-position title=list-style-position>list-style-position</a> on the list item can make the marker box positioned,
which can have an effect on the computed value of display.
<p> The <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element is only created on <a data-link-type=dfn href=#list-item title="list items">list items</a>.
On any other element,
the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element’s <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property must compute to <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>,
which suppresses its creation.
<div class=example>
In the following example,
the content is centered within a marker box of a fixed width.
This document:
<pre> <style>
li::marker {
content: "(" counter(counter) ")";
width: 6em;
text-align: center;
}
li {
display: list-item;
counter-increment: counter;
}
</style>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
</pre>
<p> should render something like this:
<pre>
(1) This is the
first item.
(2) This is the
second item.
(3) This is the
third item.
</pre> </div>
<div class=example>
In this example, markers are used to number paragraphs that are designated as "notes":
<pre> <style>
p { margin-left: 12 em; }
p.note {
display: list-item;
counter-increment: note-counter;
}
p.note::marker {
content: "Note " counter(note-counter) ":";
text-align: left;
width: 10em;
}
</style>
<p>This is the first paragraph in this document.</p>
<p class="note">This is a very short document.</p>
<p>This is the end.</p>
</pre>
<p> It should render something like this:
<pre>
This is the first paragraph
in this document.
Note 1: This is a very short
document.
This is the end.
</pre> </div>
<div class=example>
By using the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element,
a list’s markers can be positioned much more flexibly,
and even be styled independently from the text of the list item itself:
<pre> <style>
p { margin-left: 8em } /* Make space for counters */
li { list-style-type: lower-roman; }
li::marker { margin: 0 3em 0 0; color: blue; font-weight:bold; }
</style>
<p>This is a long preceding paragraph ...</p>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
<p>This is a long following paragraph ...</p>
</pre>
<p> The preceding document should render something like this:
<pre>
This is a long preceding
paragraph ...
<span style=color:blue;font-weight:bold;>i.</span> This is the first item.
<span style=color:blue;font-weight:bold;>ii.</span> This is the second item.
<span style=color:blue;font-weight:bold;>iii.</span> This is the third item.
This is a long following
paragraph ...
</pre>
<p> Previously the only way to style a marker was through inheritance;
one had to put the desired marker styling on the list item,
and then revert that on a wrapper element around the list item’s actual contents.
Non-inherited properties like <a class=property data-link-type=propdesc href=http://www.w3.org/TR/CSS21/box.html#propdef-margin title=margin>margin</a> couldn’t be adjusted at all on the marker.
</div>
<h3 class="heading settled heading" data-level=6.1 id=content-property><span class=secno>6.1 </span><span class=content>
Generating the value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property</span><a class=self-link href=#content-property></a></h3>
<p> The <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element’s <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property is set according to its <dfn data-dfn-type=dfn data-noexport="" id=default-contents>default contents<a class=self-link href=#default-contents></a></dfn>,
which are defined by the <a class=property data-link-type=propdesc href=#propdef-list-style-image title=list-style-image>list-style-image</a> and <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a> properties:
<dl>
<dt>an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-images-3/#image-type title="<image>"><image></a>
<dd>
The computed value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property is the computed value of the <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-images-3/#image-type title="<image>"><image></a>.
<dt>a <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#string-value title="<string>"><string></a>
<dd>
The computed value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property is the <string>.
<dt>a <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-counter-styles-3/#typedef-counter-style title="<counter-style>"><counter-style></a>
<dd>
The computed value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property is
<code><a class="production css-code" data-link-type=type href=#typedef-counter-prefix title="<counter-prefix>"><counter-prefix></a> counter(list-item, <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-counter-styles-3/#typedef-counter-style title="<counter-style>"><counter-style></a>) <a class="production css-code" data-link-type=type href=#typedef-counter-suffix title="<counter-suffix>"><counter-suffix></a></code>,
where <dfn class=css-code data-dfn-type=type data-export="" id=typedef-counter-prefix no-export=""><counter-prefix><a class=self-link href=#typedef-counter-prefix></a></dfn> and <dfn class=css-code data-dfn-type=type data-export="" id=typedef-counter-suffix no-export=""><counter-suffix><a class=self-link href=#typedef-counter-suffix></a></dfn> are the values of the <span class=css data-link-type=maybe title=@counter-style/prefix>@counter-style/prefix</span> and <span class=css data-link-type=maybe title=@counter-style/suffix>@counter-style/suffix</span> descriptors for the counter style.
<dt><a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>
<dd>
The computed value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property is <a class=css data-link-type=maybe href=#valuedef-none0 title=none>none</a>.
</dl>
<p> If the computed value of <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> was an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-images-3/#image-type title="<image>"><image></a>,
and it ends up resolving to an <a data-link-type=dfn href=http://dev.w3.org/csswg/css-images-4/#invalid-image title="invalid image">invalid image</a>,
the used value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property
is as above,
but with the <a data-link-type=dfn href=#default-contents title="default contents">default contents</a> determined solely by <a class=property data-link-type=propdesc href=#propdef-list-style-type title=list-style-type>list-style-type</a>.
<div class=example>
Given the following style sheet:
<pre> li { display: list-item; list-style-type: decimal /* initial value */; }
li::marker { content: normal /* initial value */; }
</pre>
<p> And the following document fragment:
<pre><li>List Item</li></pre>
<p> The computed value of the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property on the <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-element of the <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-li-element title=li>li</a> is:
<pre>counter(list-item, decimal) "."</pre> </div>
<h2 class="heading settled heading" data-level=7 id=positioning-markers><span class=secno>7 </span><span class=content>
Positioning Markers</span><a class=self-link href=#positioning-markers></a></h2>
<p> This section introduces a new positioning scheme,
designed to model the way in which <a class=css data-link-type=propdesc href=#propdef-list-style-position title=list-style-position>list-style-position:outside</a> list markers were traditionally positioned in CSS 2.1.
Outside list markers now have their positioning defined in terms of this new value.
<p> The new positioning scheme defined in this section can be used on all elements,
not just <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-elements.
For example, this can be used to position explicit elements serving as markers in a legal document,
so that the list item has a marker whose value is guaranteed to be correct regardless of whether the CSS is applied
(often a requirement in legal documents),
but which is positioned like a native CSS marker.
<h3 class="heading settled heading" data-level=7.1 id=position-marker><span class=secno>7.1 </span><span class=content>
The <a class=css data-link-type=maybe href=#valuedef-marker title=marker>marker</a> value for <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a></span><a class=self-link href=#position-marker></a></h3>
<table class="definition propdef partial"><tr><th>Name:<td><a class=css-code data-link-type=property href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a><tr><th>New values:<td>marker<tr><th>Computed value:<td>see prose, otherwise same as normal</table>
<p> The <dfn class=css-code data-dfn-for=position data-dfn-type=value data-export="" id=valuedef-marker>marker<a class=self-link href=#valuedef-marker></a></dfn> value for <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a> depends on the element it is set on having a <a data-link-type=dfn href=#list-item title="list item">list item</a> ancestor.
If the specified value of <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a> is <a class=css data-link-for=position data-link-type=maybe href=#valuedef-marker title=marker>marker</a>
and the element does not have a <a data-link-type=dfn href=#list-item title="list item">list item</a> ancestor,
<a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position</a> must compute to <span class=css data-link-for=position data-link-type=maybe title=relative>relative</span> on the element.
An element with <a class=css data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position:marker</a> counts as <a href=http://www.w3.org/TR/CSS21/visuren.html#absolutely-positioned>absolutely positioned</a>.
<p> To calculate the marker’s position, we must first define a few terms:
<dl>
<dt><dfn data-dfn-type=dfn data-noexport="" id=ancestor-list-item>ancestor list item<a class=self-link href=#ancestor-list-item></a></dfn>
<dd>The <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a> is the marker’s nearest list item ancestor element.
<dt><dfn data-dfn-type=dfn data-noexport="" id=marker-positioning-reference-element>marker positioning reference element<a class=self-link href=#marker-positioning-reference-element></a></dfn>
<dd>
If the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a> has <a class=css data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side:list-item</a>,
the <a data-link-type=dfn href=#marker-positioning-reference-element title="marker positioning reference element">marker positioning reference element</a> is the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a>.
<p> Otherwise, if the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a> has <a class=css data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side:list-container</a> and has a parent element,
the <a data-link-type=dfn href=#marker-positioning-reference-element title="marker positioning reference element">marker positioning reference element</a> is the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item’s">ancestor list item’s</a> parent.
<p> Otherwise, the <a data-link-type=dfn href=#marker-positioning-reference-element title="marker positioning reference element">marker positioning reference element</a> is the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a>.
<dt><dfn data-dfn-type=dfn data-noexport="" id=list-item-positioning-edge>list item positioning edge<a class=self-link href=#list-item-positioning-edge></a></dfn>
<dd>
The border edge of the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a> corresponding to the "start" or "head" edge of the <a data-link-type=dfn href=#marker-positioning-reference-element title="marker positioning reference element">marker positioning reference element</a>,
whichever is in the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item’s">ancestor list item’s</a> inline axis.
<dt><dfn data-dfn-type=dfn data-noexport="" id=marker-positioning-edge>marker positioning edge<a class=self-link href=#marker-positioning-edge></a></dfn>
<dd>
The outer edge of the marker that’s on the opposite side from the <a data-link-type=dfn href=#list-item-positioning-edge title="list item positioning edge">list item positioning edge</a>.
For example, if the <a data-link-type=dfn href=#list-item-positioning-edge title="list item positioning edge">list item positioning edge</a> ended up being the left border edge of the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a>,
the <a data-link-type=dfn href=#marker-positioning-edge title="marker positioning edge">marker positioning edge</a> would be the right margin edge of the marker.
</dl>
<p> The marker’s position in the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a>’s block axis
is calculated according to the <a href=http://www.w3.org/TR/CSS21/visuren.html#normal-flow>normal flow</a>.
<p> The marker’s position in the <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item’s">ancestor list item’s</a> inline axis must be set such that
the <a data-link-type=dfn href=#marker-positioning-edge title="marker positioning edge">marker positioning edge</a> is flush with the <a data-link-type=dfn href=#list-item-positioning-edge title="list item positioning edge">list item positioning edge</a>.
<p class=note> Note: The purpose of this somewhat convoluted definition is to position the marker flush against its list item,
and then when "marker-side:list-container",
keep all the markers for a given list on the same side of their list items even in mixed-direction text,
so that authors can specify padding on only one side of the list container and still ensure their markers are visible.
And on top of all that,
do something sane in the face of potentially differing writing-modes on the marker, list item, and container.
<p> All elements or pseudo-elements with <a class=css data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position:marker</a>
that share a common <a data-link-type=dfn href=#ancestor-list-item title="ancestor list item">ancestor list item</a>
are known as <dfn data-dfn-type=dfn data-noexport="" id=associated-marker title=associated-marker>markers associated with that list item<a class=self-link href=#associated-marker></a></dfn>.
<p> The <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#top title=top>top</a>, <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#right title=right>right</a>, <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#bottom title=bottom>bottom</a>, and <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#left title=left>left</a> properties specify offsets
relative to the top, right, bottom, and left edges (respectively) of the element itself,
similar to how relative positioning works.
<div class=example>
<a class=css data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position:marker</a> can be used when the precise list marker is important for the content,
not a stylistic choice,
but the normal <em>appearance</em> of lists is still desired.
For example, this trimmed snippet of the US Code of Laws may be marked up as the following in HTML:
<pre> <style>
ol { list-style: none; }
.marker { position: marker; }
</style>
<ol>
<li>
<span class='marker'>(a)</span> Definitions.— For purposes of this section—<wbr><ol>
<li><span class='marker'>(1)</span> the term “agency” means agency as...
<li><span class='marker'>(2)</span> the term “individual” means a citizen...
</ol>
<li>
<span class='marker'>(b)</span> Conditions of Disclosure.— No agency shall disclose...
<ol>
<li><span class='marker'>(1)</span> to those officers and employees of the agency...
<li><span class='marker'>(2)</span> required under section 552 of this title;
</ol>
</ol>
</pre>
<p> The preceding document should render something like this:
<pre> (a) Definitions.— For purposes of this section—<wbr>(1) the term “agency” means agency as...
(2) the term “individual” means a citizen...
(b) Conditions of Disclosure.— No agency shall disclose...
(1) to those officers and employees of the agency...
(2) required under section 552 of this title;
</pre>
<p> Importantly, even if the stylesheet is unavailable,
the list markers will appear the same
(though they will be positioned slightly differently),
so other documents can refer to those list markers
and be confident that the reference will always be resolvable.
</div>
<h3 class="heading settled heading" data-level=7.2 id=marker-side><span class=secno>7.2 </span><span class=content>
The <a class=property data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side</a> property</span><a class=self-link href=#marker-side></a></h3>
<p> By default, elements or <a class=css data-link-type=maybe href=#selectordef-marker title=::marker>::marker</a> pseudo-elements with <a class=css data-link-type=propdesc href=http://dev.w3.org/csswg/css-position-3/#position title=position>position:marker</a>
position themselves according to their list item’s directionality.
However, if the list item is grouped with several other list items which may have different directionality
(for example, multiple <li>s with different "dir" attributes in an <ol> in HTML),
it is sometimes more useful to have all the markers line up on one side,
so the author can specify a single "gutter" on that side
and be assured that all the markers will lie in that gutter and be visible.
The <a class=property data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side</a> property defined in this section allows an author to control this,
switching list items to positioning their markers based off the list container’s directionality instead.
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-marker-side>marker-side<a class=self-link href=#propdef-marker-side></a></dfn><tr><th>Value:<td>list-item | list-container<tr><th>Initial:<td>list-item<tr><th>Applies to:<td><a data-link-type=df
8026
n href=#list-item title="list items">list items</a><tr><th>Inherited:<td>yes<tr><th>Media:<td>visual<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a</table>
<dl data-dfn-for=marker-side data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=marker-side data-dfn-type=value data-export="" id=valuedef-list-item>list-item<a class=self-link href=#valuedef-list-item></a></dfn>
<dd>
Any <a data-link-type=dfn href=#associated-marker title=associated-marker>markers associated with the list item</a> base their positioning off of the directionality of the list item.
<dt><dfn class=css-code data-dfn-for=marker-side data-dfn-type=value data-export="" id=valuedef-list-container>list-container<a class=self-link href=#valuedef-list-container></a></dfn>
<dd>
The <a data-link-type=dfn href=#associated-marker title=associated-marker>associated markers</a> instead base their positioning off of the directionality of the list item’s parent element.
The normative meaning of this is specified in the section defining <a href=#position-marker>position:marker</a>.
</dl>
<div class=example>
Here is an example of the effect that <a class=property data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side</a> can have on a list.
Both of the following example renderings are generated from the following HTML,
with the only difference being the value of <a class=property data-link-type=propdesc href=#propdef-marker-side title=marker-side>marker-side</a> on the list:
<pre> <ul>
<li>english one
<li dir=rtl>OWT WERBEH
<li>english three
<li dir=rtl>RUOF WERBEH
</ul>
</pre>
<table class=data style="width: 35em;">
<thead>
<tr>
<th>list-item
<th>list-container
<tbody>
<tr>
<td style="border-right: thin solid">
<pre>
* english one
OWT WERBEH *
* english three
RUOF WERBEH *</pre> <td>
<pre>
* english one
* OWT WERBEH
* english three
* RUOF WERBEH</pre> </table>
</div>
<h2 class="heading settled heading" data-level=8 id=counter><span class=secno>8 </span><span class=content>
Automatic Numbering With Counters</span><a class=self-link href=#counter></a></h2>
<p> A <dfn data-dfn-type=dfn data-export="" id=counter0>counter<a class=self-link href=#counter0></a></dfn> is a special concept
used, among other things, to automatically number list items in CSS.
Every element has a collection of zero or more counters,
which are inherited through the document tree in a way similar to inherited property values.
They are created and manipulated with the <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a>, <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a> and <a class=property data-link-type=propdesc href=#propdef-counter-reset title=counter-reset>counter-reset</a> properties,
and used with the <a class=css data-link-type=maybe href=#funcdef-counter title=counter()>counter()</a> and <a class=css data-link-type=maybe href=#funcdef-counters title=counters()>counters()</a> functions.
Counters have a name,
an integer value,
a creator element,
and possibly another counter nested inside themselves.
<h3 class="heading settled heading" data-level=8.1 id=counter-properties><span class=secno>8.1 </span><span class=content>
Manipulating Counters: the <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a>, <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a> and <a class=property data-link-type=propdesc href=#propdef-counter-reset title=counter-reset>counter-reset</a> properties</span><a class=self-link href=#counter-properties></a></h3>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-counter-reset>counter-reset<a class=self-link href=#propdef-counter-reset></a></dfn><tr><th>Value:<td>[ <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a>? ]+ | none<tr><th>Initial:<td>none<tr><th>Applies to:<td>all elements<tr><th>Inherited:<td>no<tr><th>Media:<td>all<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a</table>
<p> The <a class=property data-link-type=propdesc href=#propdef-counter-reset title=counter-reset>counter-reset</a> property <a data-link-type=dfn href=#create-a-new-counter title="create a new counter">creates new counters</a> on an element.
Its values are defined as follows:
<dl data-dfn-for=counter-reset data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for=counter-reset data-dfn-type=value data-export="" id=valuedef-none2>none<a class=self-link href=#valuedef-none2></a></dfn>
<dd>
This element does not create any new counters.
<dt><dfn class=css-code data-dfn-for=counter-reset data-dfn-type=value data-export="" id=valuedef-custom-ident-integer0><a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a>?<a class=self-link href=#valuedef-custom-ident-integer0></a></dfn>
<dd>
The element <a data-link-type=dfn href=#create-a-new-counter title="create a new counter">creates one or more new counters</a>.
Each <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> names a new counter to be created.
<p> If an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a> is provided after an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a>,
the starting value of the new counter is that integer.
Otherwise, the starting value of the new counter is <span class=css data-link-type=maybe title=0>0</span>.
<p> Implementations may have implementation-specific limits
on the maximum or minimum value of a counter.
If an increment would push the counter’s value beyond these limits,
the increment must be ignored,
and the counter’s value remain unchanged.
</dl>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-counter-set>counter-set<a class=self-link href=#propdef-counter-set></a></dfn><tr><th>Value:<td>[ <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a>? ]+ | none<tr><th>Initial:<td>none<tr><th>Applies to:<td>all elements<tr><th>Inherited:<td>no<tr><th>Media:<td>all<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a</table>
<table class="definition propdef"><tr><th>Name:<td><dfn class=css-code data-dfn-type=property data-export="" id=propdef-counter-increment>counter-increment<a class=self-link href=#propdef-counter-increment></a></dfn><tr><th>Value:<td>[ <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a>? ]+ | none<tr><th>Initial:<td>none<tr><th>Applies to:<td>all elements<tr><th>Inherited:<td>no<tr><th>Media:<td>all<tr><th>Computed value:<td>specified value<tr><th>Percentages:<td>n/a</table>
<p> The <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a> and <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a> properties
manipulate the value of existing counters.
They only create new counters if there is no counter of the given name on the element yet.
Their values are defined as follows:
<dl data-dfn-for="counter-set counter-increment" data-dfn-type=value>
<dt><dfn class=css-code data-dfn-for="counter-set counter-increment" data-dfn-type=value data-export="" id=valuedef-none>none<a class=self-link href=#valuedef-none></a></dfn>
<dd>
This element does not alter the value of any counters.
<dt><dfn class=css-code data-dfn-for="counter-set counter-increment" data-dfn-type=value data-export="" id=valuedef-custom-ident-integer><a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a> <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a>?<a class=self-link href=#valuedef-custom-ident-integer></a></dfn>
<dd>
The element alters the value of one or more counters on it.
If there is not currently a counter of the given name on the element,
the element <a data-link-type=dfn href=#create-a-new-counter title="create a new counter">creates a new counter</a> of the given name
with a starting value of <span class=css data-link-type=maybe title=0>0</span>
(though it may then immediately set or increment that value to something different).
<p> If an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-syntax-3/#typedef-integer title="<integer>"><integer></a> is provided after an <a class="production css-code" data-link-type=type href=http://dev.w3.org/csswg/css-values-3/#identifier-value title="<custom-ident>"><custom-ident></a>,
it sets the innermost counter of the given name’s value to that integer (for <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a>)
or increments the value of the innermost counter of the given name by that integer (for <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a>).
Otherwise,
the innermost counter of the given name’s value is set to <span class=css data-link-type=maybe title=0>0</span> (for <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a>)
or incremented by <span class=css data-link-type=maybe title=1>1</span> (for <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a>).
</dl>
<div class=example>
<p>This example shows a way to number chapters and sections with "Chapter 1", "1.1", "1.2", etc.
<pre> h1::before {
content: "Chapter " counter(chapter) ". ";
counter-increment: chapter; /* Add 1 to chapter */
counter-reset: section; /* Set section to 0 */
}
h2::before {
content: counter(chapter) "." counter(section) " ";
counter-increment: section;
}
</pre> </div>
<p> Inheriting counters must be done <em>before</em> resetting counters,
which must be done <em>before</em> setting counters,
which must be done <em>before</em> incrementing counters,
which must be done <em>before</em> using counters
(for example, in the <a class=property data-link-type=propdesc href=http://dev.w3.org/csswg/css-content-3/#content title=content>content</a> property).
<div class=note>
The counter properties follow the cascading rules as normal.
Thus, due to cascading, the following style sheet:
<div class=example>
<pre> h1 { counter-reset: section -1 }
h1 { counter-reset: imagenum 99 }
</pre> </div>
<p> will only reset <span class=css data-link-type=maybe title=imagenum>imagenum</span>.
To reset both counters,
they have to be specified together:
<div class=example>
<pre>H1 { counter-reset: section -1 imagenum 99 }</pre> </div>
<p> The same principles apply to the <a class=property data-link-type=propdesc href=#propdef-counter-set title=counter-set>counter-set</a> and <a class=property data-link-type=propdesc href=#propdef-counter-increment title=counter-increment>counter-increment</a> properties.
</div>
<h3 class="heading settled heading" data-level=8.2 id=creating-counters><span class=secno>8.2 </span><span class=content>
Creating and Inheriting Counters</span><a class=self-link href=#creating-counters></a></h3>
<p> Every element has a (possibly empty) set of counters.
Like many other CSS values,
an element can inherit counters from another element.
However, unlike other CSS values,
the method that counters are inherited is somewhat complex.
A counter and its value are inherited <em>separately</em>,
possibly from different elements.
<p> If an element has a previous sibling,
it must inherit all of the sibling’s counters.
Otherwise, if the element has a parent,
it must inherit all of the parent’s counters.
Otherwise, the element must have an empty set of counters.
<p> The element then inherits counter <em>values</em>
from the immediately preceding element <strong>in document order</strong>.
This must be done by examining the set of counters that the immediately preceding element has,
and, for every counter that exists in both the element’s set and the preceding element’s set,
giving the element’s counter the same value.
(If an element is the first element in the document,
and thus has no immediately preceding element,
it also doesn’t have a parent or a previous sibling,
and thus no counters to begin with.)
<div class=example id=counter-inheritance-example><a class=self-link href=#counter-inheritance-example></a>
Take the following code as an example:
<pre> <ul style='counter-reset: example 0;'>
<b class=foo><li id='foo' style='counter-increment: example;'></b>
foo
<b class=bar><div id='bar' style='counter-increment: example;'>bar</div></b>
</li>
<b class=baz><li id='baz'></b>
baz
</li>
</ul>
</pre>
<p> Recall that "in document order" turns a document tree into an ordered list,
where an element comes before its children,
and its children come before its next sibling.
In other words,
for a language like HTML,
its the order in which the parser encounters start tags as it reads the document.
<p> In here, the <code><ul></code> element establishes a new counter named "example",
and sets its value to 0.
The <b class=foo>"foo"</b> element, being the first child of the <code><ul></code>,
inherits this counter.
Its parent is also its immediately preceding element in document order,
so it inherits the value 0 with it,
and then immediately increments the value to 1.
<p> The same happens with the <b class=bar>"bar"</b> element.
It inherits the "example" counter from <b class=foo>"foo"</b>,
and inherits the value 1 from it as well
and increments it to 2.
<p> However, the <b class=baz>"baz"</b> element is a bit different.
It inherits the "example" counter from the <b class=foo>"foo"</b> element,
its previous sibling.
However, rather than inheriting the value 1 from <b class=foo>"foo"</b> along with the counter,
in inherits the value 2 from <b class=bar>"bar"</b>, the previous element in document order.
<p> This behavior allows a single counter to be used throughout a document,
continuously incrementing,
without the author having to worry about the nested structure of their document.
</div>
<p> Elements can create additional counters on themselves,
which can then be passed onto siblings or children.
To <dfn data-dfn-type=dfn data-noexport="" id=create-a-new-counter>create a new counter<a class=self-link href=#create-a-new-counter></a></dfn>,
specify an element that’s creating it,
a name,
and a starting value.
The effect depends on what other counters of that name exist on the element:
<p> <ul>
<li>
If no counters of that name exist on the element,
create a new counter with that name on the element.
<li>
Otherwise, if a counter of that name exists on the element,
and it was created by a preceding sibling,
replace the innermost counter of that name on the element
with a newly-created counter with that name.
<li>
Otherwise, create a new counter with that name
and nest it inside of the innermost counter with that name.
</ul>
<p> Regardless, the value of the new counter is set to the provided starting value.
<h3 class="heading settled heading" data-level=8.3 id=nested-counters><span class=secno>8.3 </span><span class=content>
Nested Counters</span><a class=self-link href=#nested-counters></a></h3>
<p> Counters are "self-nesting";
<a data-link-type=dfn href=#create-a-new-counter title="create a new counter">creating a new counter</a> in an element
which already has a counter with the same name
simply creates a new counter of the same name,
nested inside the existing counter.
This is important for situations like lists in HTML,
where lists can be nested inside lists to arbitrary depth.
It would be impossible to define uniquely named counters for each level.
As explained in a later section,
the <a class=css data-link-type=maybe href=#funcdef-counter title=counter()>counter()</a> function only uses the innermost counter of a given name on the element,
but the <a class=css data-link-type=maybe href=#funcdef-counters title=counters()>counters()</a> function uses all counters of a given name that contain the element.
<div class=example>
Thus, the following suffices to number nested list items.
The result is very similar to that of setting <a class=css data-link-type=propdesc href=http://www.w3.org/TR/CSS21/visuren.html#propdef-display title=display>display:list-item</a> and <a class=css data-link-type=propdesc href=#propdef-list-style title=list-style>list-style: inside</a> on the LI element:
<pre> ol { counter-reset: item }
li { display: block }
li::before { content: counter(item) ". "; counter-increment: item }
</pre>
<p> In this example,
an <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-ol-element title=ol>ol</a> will create a counter,
and all children of the <a data-link-type=element href=http://www.w3.org/html/wg/drafts/html/CR/grouping-content.html#the-ol-element title=ol>ol</a> will refer to that counter.
</div>
<div class=example id=counter-nesting-example><style scoped>
#counter-nesting-example .ol { background: rgba(0,0,0,.1); margin: .5em 0; padding: .2em .5em; }
#counter-nesting-example .li > .ol { margin: 0 0 0 1em; }
#counter-nesting-example .li { list-style: none; margin-left: 1em;}
</style>