[CSS2] stop requiring some old IDs

This drops IDs for: index xrefs (x[n]), bits of generated content
(annoying-warning, minitoc, W3C-doctype), refs (ref-*), and the index
sections (index-[A]). Only the first might be referenced at all, and
unfortunately they are not unique across all pages unlike all other
anchors.

Author: gsnedders

css2/Overview.bs

@@ -19,7 +19,7 @@ Abstract: See below.
 Required IDs: abs-non-replaced-height, abs-non-replaced-width, absolutely-positioned,
   absolute-positioning, absrel-units, abs-replaced-height, abs-replaced-width, abstract,
   acknowledgements, actual-value, addressing, adjacent-selectors, algorithm, alignment-prop,
-  all-media-group, allowed-page-breaks, almost, ancestor, angles, annoying-warning, anonymous,
+  all-media-group, allowed-page-breaks, almost, ancestor, angles, anonymous,
   anonymous-block-level, anonymous-boxes, applies-to, at-import, at-media-rule, at-rules,
   attribute, attribute-selectors, audio-media-group, aural-intro, aural-media-group, aural-tables,
   author, authoring, AutoNumber2, auto-table-layout, background, background-properties,
@@ -54,19 +54,15 @@ Required IDs: abs-non-replaced-height, abs-non-replaced-width, absolutely-positi
   img-flow-float, img-flow-generic, img-flow-relative, img-flow-static, img-frame,
   img-inline-layout, img-list-inout, img-overflow1, img-overflow2, img-page-info, img-pixel1,
   img-pixel2, img-table1, img-table-overlap, img-tbl-border-conflict, img-tbl-empty,
-  img-tbl-layers, img-tbl-spacing, img-tbl-width, important-rules, indentation-prop, index-;,
-  index-<, index-=, index->, index-?, index-@, index-[, index-\, index-], index-^, index-_,
-  index-`, index-a, index-b, index-c, index-d, index-e, index-f, index-g, index-h, index-i,
-  index-j, index-k, index-l, index-m, index-n, index-o, index-p, index-q, index-r, index-s,
-  index-t, index-u, index-v, index-w, index-x, index-y, index-z, informative, inheritance,
+  img-tbl-layers, img-tbl-spacing, img-tbl-width, important-rules, indentation-prop, informative, inheritance,
   inherited-prop, initial-containing-block, initial-value, inlineblock-replaced-width,
   inlineblock-width, inline-box, inline-boxes, inline-box-height, inline-formatting, inline-level,
   inline-non-replaced, inline-replaced-height, inline-replaced-width, inline-width, inner-edge,
   interactive-media-group, internal, internal-table-element, intrinsic, keywords, known-errors,
   lang, layers, leading, length-units, line-box, line-height, lining-striking-props,
   link-pseudo-classes, lists, list-style, magnification, margin-edge, margin-properties,
   matching-attrs, media-applies, media-groups, media-intro, media-sheets, media-types,
-  message-entity, minitoc, min-max-heights, min-max-widths, mixing-props, model, monospace-def,
+  message-entity, min-max-heights, min-max-widths, mixing-props, model, monospace-def,
   mpb-examples, multi-font-inline-height, new, normal-block, normal-flow, normative,
   notes-and-examples, numbers, organization, outer-edge, outline-focus, outlines, outside-page-box,
   overflow, overflow-clipping, overlapping-example, padding-edge, padding-properties, page-area,
@@ -105,12 +101,7 @@ Required IDs: abs-non-replaced-height, abs-non-replaced-width, absolutely-positi
   propdef-word-spacing, propdef-z-index, properties, property, property-defs, pseudo-classes,
   pseudo-class-selectors, pseudo-elements, pseudo-element-selectors, q1.0, q10.0, q11.0, q14.0,
   q15.0, q16.0, q17.0, q18.0, q19.0, q2.0, q20.0, q22.0, q23.0, q24.0, q25.0, q25.4, q26.0, q27.0,
-  q3.0, q4, q4.0, q5.0, q6.0, q7.0, q9.0, quotes, quotes-insert, quotes-specify, reading, ref-2318,
-  ref-BCP47, ref-CHARSETS, ref-COLORIMETRY, ref-CSS1, ref-CSS2, ref-CSS3COLOR, ref-CSS3LIST,
-  ref-CSS3SEL, ref-CSS3SPEECH, ref-DOM-LEVEL-3-CORE, ref-FLEX, ref-HTML4, ref-ICC42, ref-ISO10646,
-  ref-ISO8879, ref-MATH30, ref-MEDIAQ, ref-P3P, ref-PNG, ref-RFC2045, ref-RFC2119, ref-RFC2616,
-  ref-RFC3986, ref-SRGB, ref-SVG11, ref-UAAG10, ref-UAX9, ref-UNICODE, ref-WCAG20, ref-XHTML,
-  ref-XML10, ref-XMLID, ref-XMLNAMESPACES, ref-YACC, relative-positioning, rendered-content,
+  q3.0, q4, q4.0, q5.0, q6.0, q7.0, q9.0, quotes, quotes-insert, quotes-specify, reading, relative-positioning, rendered-content,
   replaced-element, root, root-height, rule-sets, run-in, sample, sans-serif-def, scanner, scope,
   selector-syntax, separated-borders, serif-def, shorthand, shrink-to-fit-float, sibling,
   simple-selector, small-caps, source-document, spacing-props, spatial-props, speak-headers,
@@ -140,11 +131,8 @@ Required IDs: abs-non-replaced-height, abs-non-replaced-width, absolutely-positi
   value-def-table-row, value-def-table-row-group, value-def-time, value-def-top,
   value-def-upper-latin, value-def-upper-roman, value-def-uri, values, value-stages,
   vendor-keyword-history, vendor-keywords, viewport, visibility, visual-media-group,
-  visual-model-intro, voice-char-props, volume-props, W3C-doctype, whitespace, white-space-model,
-  white-space-prop, width-constraints, width-layout, x0, x1, x10, x11, x12, x13, x14, x15, x16,
-  x17, x18, x19, x2, x20, x21, x22, x23, x24, x25, x26, x27, x28, x29, x3, x30, x31, x32, x33, x34,
-  x35, x36, x37, x38, x39, x4, x40, x41, x42, x43, x44, x45, x46, x47, x48, x49, x5, x50, x51, x52,
-  x53, x54, x55, x56, x57, x58, x59, x6, x7, x8, x9, xml-tutorial, z-index
+  visual-model-intro, voice-char-props, volume-props, whitespace, white-space-model,
+  white-space-prop, width-constraints, width-layout, xml-tutorial, z-index
 </pre>
 
 <pre class=biblio>