-
Notifications
You must be signed in to change notification settings - Fork 790
Expand file tree
/
Copy pathOverview.bs
More file actions
1395 lines (1306 loc) · 62.2 KB
/
Overview.bs
File metadata and controls
1395 lines (1306 loc) · 62.2 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
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD Bikeshed 2016-09//EN">
<html lang="en">
<head>
<meta charset="utf-8" />
<title>CSS Print Profile</title>
<style type="text/css">
th { background: #005A9C; co
FE74
lor: white; }
tr.yes { background: aqua; }
tr.no { background: transparent; }
tr.enh { background: yellow; }
.new { color : blue } /* added during 11/4 pwg review */
.tableNotes { font-size: 75%;font-style: italic; margin-bottom: 0in; padding-bottom: 0}
.aTableNote { font-size: 75%; margin:0; margin-left: .125in; padding: 0;}
.editorial { display: block; font-family: arial, helvetica, sans-serif;
font-size: 80%;
margin-left: .5in; margin-right: 1in ; padding: 0.125in;
background: #FFFFDD ;
}
.editorial:after { content: "Ed."}
div.editorial pre {padding: 0; margin: 0 0 0 0;color:maroon;
font-family: helvetica, sans-serif; font-size:90%;}
table.keys td { vertical-align:top; margin-top: 5px;}
.RFC2119 { text-transform: lowercase; font-style: italic }
em em.RFC2119 { text-transform: lowercase; font-style: normal }
</style>
</head>
<body>
<pre class="metadata">
Title: CSS Print Profile
Shortname: css-mobile
Group: csswg
Level:
Status: ED
Work status: abandoned
TR: http://www.w3.org/TR/css-print/
ED: https://dev.w3.org/csswg/css-print/
Previous Version: https://www.w3.org/TR/2013/NOTE-css-print-20130314/
Editor: Elika J. Etemad, w3cid 35400
Editor: Melinda Grant, Hewlett-Packard Company
Default Biblio Status: current
Abstract:
<p>This specification defines a subset of <cite>Cascading Style
Sheets Level 2, revision 1</cite> [[!CSS21]] and <cite>CSS Paged
Media Level 3</cite> [[!CSS3PAGE]] for printing to low-cost devices.
It is designed for printing in situations where it is not feasible
or desirable to install a printer-specific driver, and for
situations were some variability in the output is acceptable.</p>
<p>This profile is designed to work in conjunction with
<cite>XHTML-Print</cite> [[XHTML-PRINT]] and defines a minimum level
of conformance as well as an extension set that provides stronger
layout control for the printing of mixed text and images, tables and
image collections.</p>
<p><strong>This profile is obsolete. Please see the latest <a
href="https://www.w3.org/TR/CSS/" >CSS Snapshot</a> for the
specifications that make up CSS.</strong></p>
Status text:
<p>Relative to the <a
href="https://www.w3.org/TR/2004/CR-css-print-20040225/" >previous
Candidate Recommendation</a>, this version adds two new features
('object-fit' and 'object-position'), synchronizes this profile with changes to
<a href="https://www.w3.org/TR/xhtml-print/" >XHTML-Print</a>,
removes redundancies with <a
href="https://www.w3.org/TR/css3-page/" >CSS Paged Media
Level 3</a> and makes miscellaneous clarifications and editorial
improvements.</p>
<p>Relative to the <a
href="https://www.w3.org/TR/2006/WD-css-print-20061013/" >previous
Working Draft</a>, this version updates the names and behavior of
'object-fit' and 'object-position' to match the Candidate
Recommendation of <a href="https://www.w3.org/TR/css3-images/" >CSS
Images and Replaced Content Level 3</a> (and <a
href="#section-images" >adds a mapping allowance</a>), and updates
references to <a href="https://www.w3.org/TR/css3-page/" >CSS Paged
Media Level 3</a> and <a href="https://www.w3.org/TR/CSS21/">CSS 2.1</a>.</p>
<p><em>At this time, the CSS Working Group does not envisage
further work on this specification and does not plan to propose it
as a W3C Recommendation.</em></p>
</pre>
<pre class="link-defaults">
spec:css-images-3; type:value; text:fill
</pre>
<pre class="anchors">
urlPrefix:https://www.w3.org/TR/2011/REC-CSS2-20110607/colors.html#propdef-
spec:CSS21; type:property; text:color
spec:CSS21; type:property; text:display
spec:CSS21; type:property; text:vertical-align
</pre>
<pre class="biblio">
{
"CSSPP": {
"title": "CSS Print Profile",
"authors": ["D. Wright", "J. Bigelow, eds."],
"publisher": "PWG",
"status": "Proposed Standard 5102.2",
"date": "28 March 2003",
"href": "http://www.pwg.org/xhtml-print/HTML-Version/CSS-Print.html"
}
}
</pre>
<!-- ****************** -->
<!-- OVERVIEW -->
<!-- ****************** -->
<h2 id="section-overview">1. Overview</h2>
<p> All sections of this document are normative unless noted as informative.
</p>
<p>This document specifies a profile of the <cite>Cascading Style Sheets,
level 2, revision 1</cite> (CSS 2.1) specification [[!CSS21]] along with
the <cite>CSS Paged Media Level 3</cite> [[!CSS3PAGE]]
and <cite>CSS Images Level 3</cite> [[!CSS3-IMAGES]]
</p>
<p>CSS 2.1 specifies how developers can author style sheets for
presenting documents across multiple devices and media types. While this is very
important, it is also important that authors have an understanding of what
features are supported on these different devices. Likewise, it is important
that similar devices operate in a similar manner. Otherwise, authors could need
to develop style sheets for each version of each device -- raising the cost of
content development and decreasing interoperability.</p>
<p>
The CSS Print Profile specifies a conformance profile for
printing in environments where it is not feasible or desirable to use a
printer-specific driver. An example of such an environment is printing to
low-cost printers from mobile phones. The profile identifies a minimum set of properties, values, selectors,
and cascading rules to support these use scenarios. This profile was designed in
conjunction with <cite>XHTML-Print</cite> [[XHTML-PRINT]])
for low cost printers that may not have a full-page buffer and that
generally print from top-to-bottom.</p>
<p> This profile also contains an enhanced layout
extension set which supports more exacting page layouts and orientations. These
features provide sufficient richness to print, for example, photo album pages
from a digital still camera or print-targeted television content.</p>
<p>Conformance to this profile means that a user agent
supports, at a minimum, the features defined in this specification.
This subject is addressed in <a href="#section-conformance">Section 2,
Conformance</a> below.</p>
<!-- ******************** -->
<!-- CONFORMANCE -->
<!-- ******************** -->
<h2 id="section-conformance">2. Conformance</h2>
<p>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 (see [[RFC2119]]). However, for readability, these
words do not appear in all uppercase letters in this
specification.</p>
<p>The primary role of a profile is to define a subset of features that provides
a minimal guarantee of interoperability. In the case of the CSS Print Profile,
this guarantee is that a conforming user agent will support the features defined
in this specification following the CSS 2.1 conformance clause ([[!CSS21]] Section 3.2), recast
and summarized below:</p>
<ol>
<li>A CSS Print Profile conforming user agent (PP-UA or more simply "printer") <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support the
<em>all</em> and <em>print</em> CSS 2.1 media types. A printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> support other
CSS 2.1 media types, as well. </li>
<li>For each source document, a printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> attempt to retrieve all associated
style sheets that are appropriate for the supported media types.
A failure to retrieve a style sheet due to problems such as
a loss of network connection <em title="SHOULD NOT in the RFC 2119 context" class="RFC2119">SHOULD NOT</em> stop the printer from processing the document.
</li>
<li>A printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> parse the style sheets according to this specification. In
particular,
the printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> recognize all CSS Print Profile at-rules, blocks,
declarations, and selectors. If a printer encounters a property that applies for
a supported media type, the printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> parse the value according to the
property definition. This means that the printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> accept all valid values
and <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> ignore declarations with invalid values. A printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> ignore rules that
apply to unsupported media types. </li>
<li>For each element in a document tree, the printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> assign a value for
every applicable property according to the property's definition and the rules
of cascading and inheritance. </li>
<li>If the source document comes with alternate style sheets (such as with the
"alternate" keyword in HTML 4.01 [[!HTML401]]), the printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em>
ignore the style sheet or treat it in some implementation dependent manner. </li></ol>
<p>As with CSS 2.1, there are qualifications to this conformance clause:</p>
<ol>
<li>Values <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> be approximated when <em title="REQUIRED in the RFC 2119 context" class="RFC2119">REQUIRED</em> by the printer.</li>
<li>The inability of a printer to implement part of this specification due to
the limitations of a particular device (e.g., a printer cannot render colors on
a monochrome page) <em title="SHALL NOT in the RFC 2119 context" class="RFC2119">SHALL NOT</em> imply non-conformance. </li>
</ol>
<p>It is <em title="RECOMMENDED in the RFC 2119 context" class="RFC2119">RECOMMENDED</em>
that authors use this conformance profile to take advantage
of forward compatibility. Authors <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> use style properties with
an understanding that the cascading rules are processed correctly and that
unknown properties and values are ignored. For example:</p>
<div class="code-example"><pre> body {
background-position: center center;
background-position: 45% 55%;
}
</pre></div>
<p>A printer that can accept percentage values for the
background-position property will process the first background-position
declaration and then replace that value with the second
background-position declaration. A printer that cannot accept percentage values will process the first
background-position declaration and ignore the second background-position
declaration.</p>
<h3 id="s2.1">2.1. Enhanced Layout Extension Conformance</h3>
<p>Some print applications require a
more exacting page layout than is available from a
minimally conforming printer (<i>e.g.,</i> photo album pages or pages from
a digital TV).
The Enhanced Layout Extension increases the number
of properties that a conforming printer <em title="MUST in the RFC 2119 context" class="RFC2119">MUST</em> support and thereby the
requirements of its memory and performance capabilities. These
added CSS constructs
are indicated with a "<em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em>" or
an increased range of values, in the CSS
Print-Enhanced columns below.</p>
<p> Printers supporting the Enhanced Layout
Extension <em
title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> also
support an <em title="OPTIONAL in the RFC 2119 context"
class="RFC2119">OPTIONAL</em>, discoverable (via some means outside the scope of
this document) Enhanced Layout Extension indicator.</p>
<!-- ******************* -->
<!-- SELECTORS -->
<!-- ******************* -->
<h2 id="section-selectors">3. Selectors</h2>
<p>In CSS 2.1, pattern matching rules determine which style rules apply to elements
in the document tree [[!CSS21]].</p>
<p>
Consideration is given to low-cost printers that might not be able
to store all the attributes of each element, but only keep the few that are necessary.
Therefore, only Enhanced Layout Extension conforming
printers <em title="MUST in the RFC 2119 context" class="RFC2119">MUST</em> support attribute selectors.
</p>
<p>
The following table summarizes CSS Print Profile selector syntax. In
addition to the selectors marked "<em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em>"
in the CSS Print or CSS Print-Enhanced columns, the CSS Print
Profile includes the CSS 2.1 grouping mechanism (See [[!CSS21]] Section 5.2.1).
</p>
<table border="1" width="80%"
summary="List of all selectors indicating which ones are supported">
<tbody>
<tr>
<th>Pattern</th>
<th>Meaning</th>
<th>Selector type</th>
<th>CSS Print</th>
<th>CSS Print-Enhanced</th>
</tr>
<tr class="yes">
<td>*</td>
<td>Matches any element</td>
<td>Universal selector</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>E</td>
<td>Matches any E element (i.e., any element of type E)</td>
<td>Type selectors</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>E F</td>
<td>Matches any F element that is a descendant of an E element</td>
<td>Descendant selectors</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>E > F</td>
<td>Matches any F element that is a child of an element E</td>
<td>Child selectors</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="enh">
<td>E[foo]</td>
<td>Matches any E element with the "foo" attribute set (whatever the
value).</td>
<td>Attribute selectors</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="enh">
<td>E[foo="warning"]</td>
<td>Matches any E element whose "foo" attribute value is exactly equal to
"warning".</td>
<td>Attribute selectors</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="enh">
<td>E[foo~="warning"]</td>
<td>Matches any E element whose "foo" attribute value is a list of
space-separated values, one of which is exactly equal to "warning".</td>
<td>Attribute selectors</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>E.classid</td>
<td>The same as E[class~=classid]</td>
<td>Class selectors</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>E#myid</td>
<td>Matches any E element id equal to "myid".</td>
<td>ID selectors</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>@page :first</td>
<td>Specifies style for the first page of a document</td>
<td>Page pseudo-classes</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
</tbody>
</table>
<h3 id="at-rules">3.1 At-rules</h3>
<p>The following table summarizes CSS Print Profile at-rule syntax.</p>
<table border="1" width="80%">
<tbody>
<tr>
<th>at-rule</th>
<th>Function</th>
<th>CSS Print</th>
<th>CSS Print-Enhanced</th></tr>
<tr class="enh">
<td>@import</td>
<td>Imports an external style sheet.</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td></tr>
<tr class="yes">
<td>@charset</td>
<td>Defines character set for the style sheet.</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td></tr>
<tr class="yes">
<td>@media</td>
<td>Groups a set of style rules to apply only to one or more particular
media.</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td></tr>
<tr class="yes">
<td>@page</td>
<td>Defines a (optionally named) page formatting context.</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td></tr>
<tr class="yes">
<td>@bottom-left-corner, @bottom-left, <br />@bottom-center, @bottom-right, @bottom-right-corner</td>
<td>Defines areas on the page within the running footer in the page's bottom margin [[!CSS3PAGE]]</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
<tr class="yes">
<td>@top-left-corner, @top-left, <br />@top-center, <br /> @top-right, <br />@top-right-corner</td>
<td>Defines areas on the page within the running header in the page's top margin [[!CSS3PAGE]]</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
</tr>
</tbody>
</table>
<!-- ******************************* -->
<!-- PROPERTIES AND VALUES -->
<!-- ******************************* -->
<h2 id="section-properties">4. Properties</h2>
<p> As with selectors, the properties a printer <em title="MUST in the RFC 2119 context" class="RFC2119">MUST</em>
support are similar to those that a mobile device <em title="MUST in the RFC 2119 context" class="RFC2119">MUST</em> support ([[CSS-MOBILE]], <a
href="http://www.w3.org/TR/css-mobile#properties">
Properties</a>) with the exception of those that don't apply to the
page or are specifically targeted at media other than the page. </p>
<p>
In some cases the allowable values for a printer are a subset of the full range of
values to match the reduced memory and performance capabilities of a low-cost printer.
</p>
<p>The following table summarizes CSS Print Profile properties and property values.
Refer to <cite>CSS Paged Media Level 3</cite> [[!CSS3PAGE]]
for the definition of the 'size' properties,
<cite>CSS Image Values and Replaced Content Level 3</cite>
[[!CSS3-IMAGES]] for the definition of the
'image-orientation', 'object-fit', and 'object-position' properties,
and CSS 2.1 [[!CSS21]]
for the definition of all other properties and values.</p>
<table border="1" width="80%">
<thead>
<tr align="center">
<th>Name</th>
<th>CSS Print</th>
<th>CSS Print-Enhanced</th>
<th>CSS Values</th>
<th>Initial value</th></tr></thead>
<tbody>
<tr class="yes">
<td>'background'</td>
<td>background-color | inherit</td>
<td>
['background-color' || 'background-image' || 'background-repeat' || 'background-position']
| inherit</td>
<td>['background-color' || 'background-image' || 'background-repeat' || 'background-attachment' || 'background-position'] | inherit</td>
<td>see individual properties</td></tr>
<tr class="yes">
<td>'background-color'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><color> | transparent | inherit</td>
<td>transparent</td></tr>
<tr class="enh">
<td>'background-image'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><uri> | none | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'background-position'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ [ <percentage> | <length> ]{1,2} | [ [top | center |
bottom] || [left | center | right] ] ] | inherit</td>
<td>0% 0%</td></tr>
<tr class="enh">
<td>'background-repeat'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>repeat | repeat-x | repeat-y | no-repeat | inherit</td>
<td>repeat</td></tr>
<tr class="enh">
<td>'border'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ <border-width> || <border-style> || [<color> |
transparent] ] | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'border-collapse'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>collapse | separate | inherit</td>
<td>collapse</td></tr>
<tr class="enh">
<td>'border-color'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[<color> | transparent]{1,4} | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'border-spacing'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> <length>? | inherit</td>
<td>0</td></tr>
<tr class="enh">
<td>'border-style'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td> none, solid </td>
<td><border-style>{1,4} | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'border-top' 'border-right' 'border-bottom' 'border-left'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ <border-width> || <border-style> || [<color> |
transparent] ] | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'border-top-color' 'border-right-color' 'border-bottom-color'
'border-left-color'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><border-color> | transparent | inherit</td>
<td>the value of the 'color' property</td></tr>
<tr class="enh">
<td>'border-top-style' 'border-right-style' 'border-bottom-style'
'border-left-style'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td>none, solid</td>
<td><border-style> | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'border-top-width' 'border-right-width' 'border-bottom-width'
'border-left-width'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><border-width> | inherit</td>
<td>medium</td></tr>
<tr class="enh">
<td>'border-width'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><border-width>{1,4} | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'bottom'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'caption-side'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>top | bottom | left | right | inherit</td>
<td>top</td></tr>
<tr class="enh">
<td>'clear'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>none | left | right | both | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'clip'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><shape> | auto | inherit</td>
<td>auto</td></tr>
<tr class="yes">
<td>'color'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><color> | inherit</td>
<td>depends on user agent</td></tr>
<tr class="yes">
<td>'content'</td>
<td>inherit | [<string> | counter(pages<a href="#table_note_0">†</a>)]+</td>
<td>inherit | [<string> | counter(pages<a href="#table_note_0">†</a>)]+</td>
<td>[ <string> | <uri> | <counter> | attr(X) |
open-quote | close-quote | no-open-quote | no-close-quote ]+ | inherit</td>
<td>empty string</td></tr>
<tr class="yes">
<td>'counter-increment'</td>
<td>"pages"<a href="#table_note_0">†</a></td>
<td>"pages"<a href="#table_note_0">†</a></td>
<td>[ <identifier> <integer> ]+ | none |
inherit</td>
<td>none</td></tr>
<tr class="yes">
<td>'counter-reset'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ <identifier> <integer>? ]+ | none | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'display'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td>inline | block | list-item | none |inherit</td>
<td>inline | block | list-item | run-in | compact | marker | table |
inline-table | table-row-group | table-header-group | table-footer-group |
table-row | table-column-group | table-column | table-cell | table-caption
| none | inherit</td>
<td>inline</td></tr>
<tr class="enh"><td>'object-fit'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em> </td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>fill | none | cover | contain</td>
<td>fill</td>
</tr>
<tr class="yes">
<td>'font'</td>
<td> [ [ 'font-style' || 'font-weight' ]? 'font-size' [ / 'line-height' ]? 'font-family' ] | inherit</td>
<td> [ [ 'font-style' || 'font-variant' || 'font-weight' ]? 'font-size' [ / 'line-height' ]? 'font-family' ] | inherit</td>
<td> [ [ 'font-style' || 'font-variant' || 'font-weight' ]? 'font-size' [ / 'line-height' ]? 'font-family' ] | caption | icon | menu | message-box |
small-caption | status-bar | inherit</td>
<td>see individual properties</td></tr>
<tr class="yes">
<td>'font-family'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em><a href="#table_note_1">*</a></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em><a href="#table_note_1">*</a></td>
<td>[[ <family-name> | <generic-family> ],]* [
<family-name> | <generic-family> ] | inherit</td>
<td>depends on user agent</td></tr>
<tr class="yes">
<td>'font-size'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a
href="#table_note_2">**</a></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a
href="#table_note_2">**</a></td>
<td><absolute-size> | <relative-size> | <length> |
<percentage> | inherit</td>
<td>medium</td></tr>
<tr class="yes">
<td>'font-style'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em><a
href="#table_note_2">**</a></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a
href="#table_note_2">**</a></td>
<td>normal | italic | oblique | inherit</td>
<td>normal</td></tr>
<tr class="enh">
<td>'font-variant'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>normal | small-caps | inherit</td>
<td>normal</td></tr>
<tr class="yes">
<td>'font-weight'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a
href="#table_note_2">**</a></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a
href="#table_note_2">**</a></td>
<td>normal | bold | bolder | lighter | 100 | 200 | 300 | 400 | 500 | 600 |
700 | 800 | 900 | inherit</td>
<td>normal</td></tr>
<tr class="yes">
<td>'height'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'image-orientation'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><angle> | auto</td>
<td>auto</td></tr>
<tr class="enh">
<td>'left'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'letter-spacing'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>normal | <length> | inherit</td>
<td>normal</td></tr>
<tr class="yes">
<td>'line-height'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>normal | <number> | <length> | <percentage> |
inherit</td>
<td>normal</td></tr>
<tr class="enh">
<td>'list-style'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ 'list-style-type' || 'list-style-position' || 'list-style-image' ] |
inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'list-style-image'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><uri> | none | inherit</td>
<td>none</td></tr>
<tr class="yes">
<td>'list-style-position'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td>inside | outside | inherit</td>
<td>outside</td></tr>
<tr class="yes">
<td>'list-style-type'</td>
<td>disc, decimal, lower-alpha, upper-alpha, none and inherit</td>
<td>disc, decimal, lower-alpha,
upper-alpha, none and inherit</td>
<td>disc | circle | square | decimal | decimal-leading-zero | lower-roman
| upper-roman | lower-greek | lower-alpha | lower-latin | upper-alpha |
upper-latin | hebrew | armenian | georgian | cjk-ideographic | hiragana |
katakana | hiragana-iroha | katakana-iroha | none | inherit</td>
<td>disc</td></tr>
<tr class="yes">
<td>'margin'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><margin-width>{1,4} | inherit</td>
<td>see individual properties</td></tr>
<tr class="yes">
<td>'margin-top' 'margin-right' 'margin-bottom' 'margin-left'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><margin-width> | inherit</td>
<td>0</td></tr>
<tr class="enh"><td>'object-position'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em> </td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>[ [<percentage> | <length> ]{1,2} | [ [top | center |
bottom] || [left | center | right] ] ]</td>
<td>50% 50%</td>
</tr>
<tr class="enh">
<td>'float'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em> </td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>left | right | none | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'orphans'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><integer> | inherit</td>
<td>2</td></tr>
<tr class="enh">
<td>'overflow'</td>
<td><em title="M
2B2
AY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td>visible | hidden | scroll |
1090E
auto | inherit</td>
<td>visible</td></tr>
<tr class="enh">
<td>'padding'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><padding-width>{1,4} | inherit</td>
<td>see individual properties</td></tr>
<tr class="enh">
<td>'padding-top' 'padding-right' 'padding-bottom' 'padding-left'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><padding-width> | inherit</td>
<td>0</td></tr>
<tr class="yes">
<td>'page'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><identifier> | auto</td>
<td>auto</td></tr>
<tr class="yes">
<td>'page-break-after'</td>
<td> auto | always | inherit </td>
<td>auto | always | inherit </td>
<td>auto | always | avoid | left | right | inherit</td>
<td>auto</td></tr>
<tr class="yes">
<td>'page-break-before'</td>
<td> auto | always | inherit </td>
<td>auto | always | inherit </td>
<td>auto | always | avoid | left | right | inherit</td>
<td>auto</td></tr>
<tr class="yes">
<td>'page-break-inside'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>avoid | auto | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'position'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> <a href="#table_note_pos">‡</a> </td>
<td>static | relative | absolute | fixed | inherit</td>
<td>static</td></tr>
<tr class="enh">
<td>'right'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
<tr class="yes">
<td>'size'</td>
<td>[<length>{1,2}| letter | legal | ledger | A4 | A5 | A3 | B4 | B5 ] | auto | portrait | inherit</td>
<td>[<length>{1,2} | letter | legal
| ledger | A4 | A5 | A3 | B4 | B5 ] | auto | portrait | landscape | inherit
</td>
<td>[<length>{1,2} | letter | legal | ledger | A4 | A5 |
A3 | B4 | B5 ] | auto | portrait | landscape | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'table-layout'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>auto | fixed | inherit</td>
<td>auto</td></tr>
<tr class="yes">
<td>'text-align'</td>
<td>left | center | inherit</td>
<td>left | right | center | inherit</td>
<td>left | right | center | justify | <string> | inherit</td>
<td>depends on user agent and writing direction</td></tr>
<tr class="yes">
<td>'text-decoration'</td>
<td>none, underline, and inherit</td>
<td>none, underline, and inherit</td>
<td>none | [ underline || overline || line-through || blink ] | inherit</td>
<td>none</td></tr>
<tr class="yes">
<td>'text-indent'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> | <percentage> | inherit</td>
<td>0</td></tr>
<tr class="enh">
<td>'text-transform'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>capitalize | uppercase | lowercase | none | inherit</td>
<td>none</td></tr>
<tr class="enh">
<td>'top'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
<tr class="enh">
<td>'vertical-align'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em><sup><a href="#table_note_vert_align">1</a></sup></td>
<td>baseline | sub | super | top | text-top | middle | bottom |
text-bottom | <percentage> | <length> | inherit</td>
<td>baseline</td></tr>
<tr class="enh">
<td>'visibility'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td>visible | hidden | collapse | inherit</td>
<td>inherit</td></tr>
<tr class="yes">
<td>'white-space'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td>normal | pre | nowrap | inherit</td>
<td>normal</td></tr>
<tr class="enh">
<td>'widows'</td>
<td><em title="MAY In The RFC 2119 Context" class="RFC2119">MAY</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em> </td>
<td><integer> | inherit</td>
<td>2</td></tr>
<tr class="yes">
<td>'width'</td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><em title="MUST In The RFC 2119 Context" class="RFC2119">MUST</em></td>
<td><length> | <percentage> | auto | inherit</td>
<td>auto</td></tr>
</tbody></table>
<p class="tableNotes"> Table Note:</p>
<p class="aTableNote" id="table_note_0">† Only the single
identifier "pages" that represents the current page number is <em title="REQUIRED in the RFC 2119 context" class="RFC2119">REQUIRED</em>.</p>
<p class="aTableNote" id="table_note_1">* It is <em title="RECOMMENDED in the RFC 2119 context" class="RFC2119">RECOMMENDED</em> that a printer minimally support
"serif," "sans-serif," and "monospace" font families. </p>
<p class="aTableNote" id="table_note_2"> ** The supported values <em title="SHOULD in the RFC 2119 context" class="RFC2119">SHOULD</em> be appropriate to
the fonts available to the printer.</p>
<p class="aTableNote" id="table_note_pos"> ‡
The printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> ignore positioned elements that are placed on the page before the position of the current element in the normal flow.
</p>
<p class="aTableNote" id="table_note_vert_align"> <sup>1</sup>
Vertical alignment is undefined across page boundaries.
</p>
<h3 id="section-images">Image Rendering Properties</h3>
<p>A previous Working Draft of this document defined
fit and fit-position properties.</p>
<p>To support legacy content using these properties,
implementations of the CSS Print Profile MAY
alias the 'object-fit' and 'object-position' properties
as defined below:</p>
<table class="data">
<thead>
<tr><th>Property/Value</th>
<th>Alias</th></tr>
</thead>
<tbody>
<tr><td>'object-fit'</td>
<td>fit</td></tr>
<tr><td>none</td>
<td>hidden</td></tr>
<tr><td>cover</td>
<td>slice</td></tr>
<tr><td>contain</td>
<td>meet</td></tr>
</tbody>
<tbody>
<tr><td>'object-position'</td>
<td>fit-position</td></tr>
</tbody>
</table>
<p>Additionally, implementations MAY override initial value
of 'object-position' (which is '50% 50%') to be '0% 0%'
by adding an appropriate rule to the UA style sheet,
if that is required for compatibility with existing content.
Similarly, if inheritance is required,
then that may also be indicated by UA style sheet rule.</p>
<div class="example">
<p>The following rule positions all images with 'object-fit' values other than ''fill'' to be top-left aligned:</p>
<pre>* { object-position: top left; }</pre>
<p>The following rules also cause 'object-position' to inherit.</p>
<pre>* { object-position: inherit; }
:root { object-position: top left; }</pre>
</div>
<!-- **************** -->
<!-- SYNTAX -->
<!-- **************** -->
<h2 id="section-syntax">5. CSS Syntax</h2>
<p>The CSS Print Profile uses the same syntax as specified in <cite>Cascading Style Sheets, Level 2, revision 1</cite> (CSS 2.1) [[!CSS21]]. The CSS Print
Profile uses a subset of the values used in CSS 2.1. Specifically:</p>
<ol>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support integer and real numbers
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#q15">Section 4.3.1</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support the following lengths
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#length-units">Section 4.3.2</a>):
<ul>
<li>px</li>
<li>em</li>
<li>ex</li>
<li>in</li>
<li>cm</li>
<li>mm</li>
<li>pt</li>
<li>pc</li>
</ul>
The printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> support other lengths. </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support percentage values
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#percentage-units">Section 4.3.3</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support URI values
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#uri">Section 4.3.4</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support
a "pages" counter value that tracks page numbers
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#counter">Section 4.3.5</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em>
support the following color values:
<ul>
<li>The 16 colors defined in HTML 4.01 [[!HTML401]] </li>
<li>A numerical RGB specification
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/syndata.html#color-units">Section 4.3.6</a>) </li>
</ul>
The printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> support other color values. The printer
<em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> support user preferences for colors
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/ui.html#system-colors">Section 18.2</a>).</li>
<li>The printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em> support user preferences for fonts
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/ui.html#system-fonts">Section 18.3</a>).</li>
</ol>
<p>Similarly, the CSS Print Profile requires that conforming user agents
support the character encoding mechanisms specified in CSS 2.1 [[!CSS21]]. Specifically
2B2
:</p>
<ol>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support priorities specified in
CSS 2.1 [[!CSS21]] to determine a
document's character encoding. </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support the
CSS 2.1 @charset rules.
However, if the character set specified by the @charset
rule of a external style sheet is not supported by the printer, the style sheet
will be ignored.
</li>
</ol>
<!-- *************************************************************** -->
<!-- ASSIGNING PROPERTY VALUES, CASCADING, and INHERITANCE -->
<!-- *************************************************************** -->
<h2 id="section-assigning">6. Assigning Property Values, Cascading, and
Inheritance</h2>
<p>In general, the CSS Print Profile uses the same cascading rules as in CSS 2.1.
Specifically:</p>
<ol>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> assign values as described in
CSS 2.1 ([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#q1">Section 6.1</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support inheritance as described in
CSS 2.1 ([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#inheritance">Section 6.2</a>). </li>
<li>A
printer supporting Enhanced Layout Extension conformance
<em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support the
CSS 2.1 @import rules as specified in CSS 2.1 ([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#at-import">Section 6.3</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support author style sheets. The printer <em title="MAY in the RFC 2119 context" class="RFC2119">MAY</em>
support user or user-agent style sheets
([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#cascade">Section 6.4</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support all
CSS 2.1 cascading mechanisms
([[!CSS21]] Sections
<a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#cascading-order">6.4.1</a>-<a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/cascade.html#q13">6.4.4</a>). </li>
</ol>
<!-- ******************** -->
<!-- MEDIA TYPES -->
<!-- ******************** -->
<h2 id="section-mediatypes">7. Media Types</h2>
<p>A CSS Print Profile conforming user agent <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> be able to process
media-dependent style sheets as specified in CSS 2.1 ([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/media.html">Section 7</a>).
Specifically:</p>
<ol>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> support the
CSS 2.1 @media rules as specified in CSS 2.1 ([[!CSS21]], <a href="http://www.w3.org/TR/2004/CR-CSS21-20040225/media.html">Section 7</a>). </li>
<li>The printer <em title="SHALL in the RFC 2119 context" class="RFC2119">SHALL</em> accept and process style sheets that target the
<code>print</code> media type. </li>