1{
2    "atrules": {
3        "charset": {
4            "prelude": "<string>"
5        },
6        "font-face": {
7            "descriptors": {
8                "unicode-range": {
9                    "comment": "replaces <unicode-range>, an old production name",
10                    "syntax": "<urange>#"
11                }
12            }
13        }
14    },
15    "properties": {
16        "-moz-background-clip": {
17            "comment": "deprecated syntax in old Firefox, https://developer.mozilla.org/en/docs/Web/CSS/background-clip",
18            "syntax": "padding | border"
19        },
20        "-moz-border-radius-bottomleft": {
21            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/border-bottom-left-radius",
22            "syntax": "<'border-bottom-left-radius'>"
23        },
24        "-moz-border-radius-bottomright": {
25            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/border-bottom-right-radius",
26            "syntax": "<'border-bottom-right-radius'>"
27        },
28        "-moz-border-radius-topleft": {
29            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/border-top-left-radius",
30            "syntax": "<'border-top-left-radius'>"
31        },
32        "-moz-border-radius-topright": {
33            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/border-bottom-right-radius",
34            "syntax": "<'border-bottom-right-radius'>"
35        },
36        "-moz-control-character-visibility": {
37            "comment": "firefox specific keywords, https://bugzilla.mozilla.org/show_bug.cgi?id=947588",
38            "syntax": "visible | hidden"
39        },
40        "-moz-osx-font-smoothing": {
41            "comment": "misssed old syntax https://developer.mozilla.org/en-US/docs/Web/CSS/font-smooth",
42            "syntax": "auto | grayscale"
43        },
44        "-moz-user-select": {
45            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/user-select",
46            "syntax": "none | text | all | -moz-none"
47        },
48        "-ms-flex-align": {
49            "comment": "misssed old syntax implemented in IE, https://www.w3.org/TR/2012/WD-css3-flexbox-20120322/#flex-align",
50            "syntax": "start | end | center | baseline | stretch"
51        },
52        "-ms-flex-item-align": {
53            "comment": "misssed old syntax implemented in IE, https://www.w3.org/TR/2012/WD-css3-flexbox-20120322/#flex-align",
54            "syntax": "auto | start | end | center | baseline | stretch"
55        },
56        "-ms-flex-line-pack": {
57            "comment": "misssed old syntax implemented in IE, https://www.w3.org/TR/2012/WD-css3-flexbox-20120322/#flex-line-pack",
58            "syntax": "start | end | center | justify | distribute | stretch"
59        },
60        "-ms-flex-negative": {
61            "comment": "misssed old syntax implemented in IE; TODO: find references for comfirmation",
62            "syntax": "<'flex-shrink'>"
63        },
64        "-ms-flex-pack": {
65            "comment": "misssed old syntax implemented in IE, https://www.w3.org/TR/2012/WD-css3-flexbox-20120322/#flex-pack",
66            "syntax": "start | end | center | justify | distribute"
67        },
68        "-ms-flex-order": {
69            "comment": "misssed old syntax implemented in IE; https://msdn.microsoft.com/en-us/library/jj127303(v=vs.85).aspx",
70            "syntax": "<integer>"
71        },
72        "-ms-flex-positive": {
73            "comment": "misssed old syntax implemented in IE; TODO: find references for comfirmation",
74            "syntax": "<'flex-grow'>"
75        },
76        "-ms-flex-preferred-size": {
77            "comment": "misssed old syntax implemented in IE; TODO: find references for comfirmation",
78            "syntax": "<'flex-basis'>"
79        },
80        "-ms-interpolation-mode": {
81            "comment": "https://msdn.microsoft.com/en-us/library/ff521095(v=vs.85).aspx",
82            "syntax": "nearest-neighbor | bicubic"
83        },
84        "-ms-grid-column-align": {
85            "comment": "add this property first since it uses as fallback for flexbox, https://msdn.microsoft.com/en-us/library/windows/apps/hh466338.aspx",
86            "syntax": "start | end | center | stretch"
87        },
88        "-ms-grid-row-align": {
89            "comment": "add this property first since it uses as fallback for flexbox, https://msdn.microsoft.com/en-us/library/windows/apps/hh466348.aspx",
90            "syntax": "start | end | center | stretch"
91        },
92        "-ms-hyphenate-limit-last": {
93            "comment": "misssed old syntax implemented in IE; https://www.w3.org/TR/css-text-4/#hyphenate-line-limits",
94            "syntax": "none | always | column | page | spread"
95        },
96        "-webkit-appearance": {
97            "comment": "webkit specific keywords",
98            "references": [
99                "http://css-infos.net/property/-webkit-appearance"
100            ],
101            "syntax": "none | button | button-bevel | caps-lock-indicator | caret | checkbox | default-button | inner-spin-button | listbox | listitem | media-controls-background | media-controls-fullscreen-background | media-current-time-display | media-enter-fullscreen-button | media-exit-fullscreen-button | media-fullscreen-button | media-mute-button | media-overlay-play-button | media-play-button | media-seek-back-button | media-seek-forward-button | media-slider | media-sliderthumb | media-time-remaining-display | media-toggle-closed-captions-button | media-volume-slider | media-volume-slider-container | media-volume-sliderthumb | menulist | menulist-button | menulist-text | menulist-textfield | meter | progress-bar | progress-bar-value | push-button | radio | scrollbarbutton-down | scrollbarbutton-left | scrollbarbutton-right | scrollbarbutton-up | scrollbargripper-horizontal | scrollbargripper-vertical | scrollbarthumb-horizontal | scrollbarthumb-vertical | scrollbartrack-horizontal | scrollbartrack-vertical | searchfield | searchfield-cancel-button | searchfield-decoration | searchfield-results-button | searchfield-results-decoration | slider-horizontal | slider-vertical | sliderthumb-horizontal | sliderthumb-vertical | square-button | textarea | textfield | -apple-pay-button"
102        },
103        "-webkit-background-clip": {
104            "comment": "https://developer.mozilla.org/en/docs/Web/CSS/background-clip",
105            "syntax": "[ <box> | border | padding | content | text ]#"
106        },
107        "-webkit-column-break-after": {
108            "comment": "added, http://help.dottoro.com/lcrthhhv.php",
109            "syntax": "always | auto | avoid"
110        },
111        "-webkit-column-break-before": {
112            "comment": "added, http://help.dottoro.com/lcxquvkf.php",
113            "syntax": "always | auto | avoid"
114        },
115        "-webkit-column-break-inside": {
116            "comment": "added, http://help.dottoro.com/lclhnthl.php",
117            "syntax": "always | auto | avoid"
118        },
119        "-webkit-font-smoothing": {
120            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/font-smooth",
121            "syntax": "auto | none | antialiased | subpixel-antialiased"
122        },
123        "-webkit-mask-box-image": {
124            "comment": "missed; https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-mask-box-image",
125            "syntax": "[ <url> | <gradient> | none ] [ <length-percentage>{4} <-webkit-mask-box-repeat>{2} ]?"
126        },
127        "-webkit-print-color-adjust": {
128            "comment": "missed",
129            "references": [
130                "https://developer.mozilla.org/en/docs/Web/CSS/-webkit-print-color-adjust"
131            ],
132            "syntax": "economy | exact"
133        },
134        "-webkit-text-security": {
135            "comment": "missed; http://help.dottoro.com/lcbkewgt.php",
136            "syntax": "none | circle | disc | square"
137        },
138        "-webkit-user-drag": {
139            "comment": "missed; http://help.dottoro.com/lcbixvwm.php",
140            "syntax": "none | element | auto"
141        },
142        "-webkit-user-select": {
143            "comment": "auto is supported by old webkit, https://developer.mozilla.org/en-US/docs/Web/CSS/user-select",
144            "syntax": "auto | none | text | all"
145        },
146        "alignment-baseline": {
147            "comment": "added SVG property",
148            "references": [
149                "https://www.w3.org/TR/SVG/text.html#AlignmentBaselineProperty"
150            ],
151            "syntax": "auto | baseline | before-edge | text-before-edge | middle | central | after-edge | text-after-edge | ideographic | alphabetic | hanging | mathematical"
152        },
153        "baseline-shift": {
154            "comment": "added SVG property",
155            "references": [
156                "https://www.w3.org/TR/SVG/text.html#BaselineShiftProperty"
157            ],
158            "syntax": "baseline | sub | super | <svg-length>"
159        },
160        "behavior": {
161            "comment": "added old IE property https://msdn.microsoft.com/en-us/library/ms530723(v=vs.85).aspx",
162            "syntax": "<url>+"
163        },
164        "clip-rule": {
165            "comment": "added SVG property",
166            "references": [
167                "https://www.w3.org/TR/SVG/masking.html#ClipRuleProperty"
168            ],
169            "syntax": "nonzero | evenodd"
170        },
171        "cue": {
172            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
173            "syntax": "<'cue-before'> <'cue-after'>?"
174        },
175        "cue-after": {
176            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
177            "syntax": "<url> <decibel>? | none"
178        },
179        "cue-before": {
180            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
181            "syntax": "<url> <decibel>? | none"
182        },
183        "cursor": {
184            "comment": "added legacy keywords: hand, -webkit-grab. -webkit-grabbing, -webkit-zoom-in, -webkit-zoom-out, -moz-grab, -moz-grabbing, -moz-zoom-in, -moz-zoom-out",
185            "references": [
186                "https://www.sitepoint.com/css3-cursor-styles/"
187            ],
188            "syntax": "[ [ <url> [ <x> <y> ]? , ]* [ auto | default | none | context-menu | help | pointer | progress | wait | cell | crosshair | text | vertical-text | alias | copy | move | no-drop | not-allowed | e-resize | n-resize | ne-resize | nw-resize | s-resize | se-resize | sw-resize | w-resize | ew-resize | ns-resize | nesw-resize | nwse-resize | col-resize | row-resize | all-scroll | zoom-in | zoom-out | grab | grabbing | hand | -webkit-grab | -webkit-grabbing | -webkit-zoom-in | -webkit-zoom-out | -moz-grab | -moz-grabbing | -moz-zoom-in | -moz-zoom-out ] ]"
189        },
190        "display": {
191            "comment": "extended with -ms-flexbox",
192            "syntax": "| <-non-standard-display>"
193        },
194        "position": {
195            "comment": "extended with -webkit-sticky",
196            "syntax": "| -webkit-sticky"
197        },
198        "dominant-baseline": {
199            "comment": "added SVG property",
200            "references": [
201                "https://www.w3.org/TR/SVG/text.html#DominantBaselineProperty"
202            ],
203            "syntax": "auto | use-script | no-change | reset-size | ideographic | alphabetic | hanging | mathematical | central | middle | text-after-edge | text-before-edge"
204        },
205        "image-rendering": {
206            "comment": "extended with <-non-standard-image-rendering>, added SVG keywords optimizeSpeed and optimizeQuality",
207            "references": [
208                "https://developer.mozilla.org/en/docs/Web/CSS/image-rendering",
209                "https://www.w3.org/TR/SVG/painting.html#ImageRenderingProperty"
210            ],
211            "syntax": "| optimizeSpeed | optimizeQuality | <-non-standard-image-rendering>"
212        },
213        "fill": {
214            "comment": "added SVG property",
215            "references": [
216                "https://www.w3.org/TR/SVG/painting.html#FillProperty"
217            ],
218            "syntax": "<paint>"
219        },
220        "fill-opacity": {
221            "comment": "added SVG property",
222            "references": [
223                "https://www.w3.org/TR/SVG/painting.html#FillProperty"
224            ],
225            "syntax": "<number-zero-one>"
226        },
227        "fill-rule": {
228            "comment": "added SVG property",
229            "references": [
230                "https://www.w3.org/TR/SVG/painting.html#FillProperty"
231            ],
232            "syntax": "nonzero | evenodd"
233        },
234        "filter": {
235            "comment": "extend with IE legacy syntaxes",
236            "syntax": "| <-ms-filter-function-list>"
237        },
238        "glyph-orientation-horizontal": {
239            "comment": "added SVG property",
240            "references": [
241                "https://www.w3.org/TR/SVG/text.html#GlyphOrientationHorizontalProperty"
242            ],
243            "syntax": "<angle>"
244        },
245        "glyph-orientation-vertical": {
246            "comment": "added SVG property",
247            "references": [
248                "https://www.w3.org/TR/SVG/text.html#GlyphOrientationVerticalProperty"
249            ],
250            "syntax": "<angle>"
251        },
252        "kerning": {
253            "comment": "added SVG property",
254            "references": [
255                "https://www.w3.org/TR/SVG/text.html#KerningProperty"
256            ],
257            "syntax": "auto | <svg-length>"
258        },
259        "letter-spacing": {
260            "comment": "fix syntax <length> -> <length-percentage>",
261            "references": [
262                "https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/letter-spacing"
263            ],
264            "syntax": "normal | <length-percentage>"
265        },
266        "marker": {
267            "comment": "added SVG property",
268            "references": [
269                "https://www.w3.org/TR/SVG/painting.html#MarkerProperties"
270            ],
271            "syntax": "none | <url>"
272        },
273        "marker-end": {
274            "comment": "added SVG property",
275            "references": [
276                "https://www.w3.org/TR/SVG/painting.html#MarkerProperties"
277            ],
278            "syntax": "none | <url>"
279        },
280        "marker-mid": {
281            "comment": "added SVG property",
282            "references": [
283                "https://www.w3.org/TR/SVG/painting.html#MarkerProperties"
284            ],
285            "syntax": "none | <url>"
286        },
287        "marker-start": {
288            "comment": "added SVG property",
289            "references": [
290                "https://www.w3.org/TR/SVG/painting.html#MarkerProperties"
291            ],
292            "syntax": "none | <url>"
293        },
294        "max-width": {
295            "comment": "fix auto -> none (https://github.com/mdn/data/pull/431); extend by non-standard width keywords https://developer.mozilla.org/en-US/docs/Web/CSS/max-width",
296            "syntax": "none | <length-percentage> | min-content | max-content | fit-content(<length-percentage>) | <-non-standard-width>"
297        },
298        "width": {
299            "comment": "per spec fit-content should be a function, however browsers are supporting it as a keyword (https://github.com/csstree/stylelint-validator/issues/29)",
300            "syntax": "| fit-content | -moz-fit-content | -webkit-fit-content"
301        },
302        "min-width": {
303            "comment": "extend by non-standard width keywords https://developer.mozilla.org/en-US/docs/Web/CSS/width",
304            "syntax": "auto | <length-percentage> | min-content | max-content | fit-content(<length-percentage>) | <-non-standard-width>"
305        },
306        "overflow": {
307            "comment": "extend by vendor keywords https://developer.mozilla.org/en-US/docs/Web/CSS/overflow",
308            "syntax": "| <-non-standard-overflow>"
309        },
310        "pause": {
311            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
312            "syntax": "<'pause-before'> <'pause-after'>?"
313        },
314        "pause-after": {
315            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
316            "syntax": "<time> | none | x-weak | weak | medium | strong | x-strong"
317        },
318        "pause-before": {
319            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
320            "syntax": "<time> | none | x-weak | weak | medium | strong | x-strong"
321        },
322        "rest": {
323            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
324            "syntax": "<'rest-before'> <'rest-after'>?"
325        },
326        "rest-after": {
327            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
328            "syntax": "<time> | none | x-weak | weak | medium | strong | x-strong"
329        },
330        "rest-before": {
331            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
332            "syntax": "<time> | none | x-weak | weak | medium | strong | x-strong"
333        },
334        "shape-rendering": {
335            "comment": "added SVG property",
336            "references": [
337                "https://www.w3.org/TR/SVG/painting.html#ShapeRenderingPropert"
338            ],
339            "syntax": "auto | optimizeSpeed | crispEdges | geometricPrecision"
340        },
341        "src": {
342            "comment": "added @font-face's src property https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face/src",
343            "syntax": "[ <url> [ format( <string># ) ]? | local( <family-name> ) ]#"
344        },
345        "speak": {
346            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
347            "syntax": "auto | none | normal"
348        },
349        "speak-as": {
350            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
351            "syntax": "normal | spell-out || digits || [ literal-punctuation | no-punctuation ]"
352        },
353        "stroke": {
354            "comment": "added SVG property",
355            "references": [
356                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
357            ],
358            "syntax": "<paint>"
359        },
360        "stroke-dasharray": {
361            "comment": "added SVG property; a list of comma and/or white space separated <length>s and <percentage>s",
362            "references": [
363                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
364            ],
365            "syntax": "none | [ <svg-length>+ ]#"
366        },
367        "stroke-dashoffset": {
368            "comment": "added SVG property",
369            "references": [
370                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
371            ],
372            "syntax": "<svg-length>"
373        },
374        "stroke-linecap": {
375            "comment": "added SVG property",
376            "references": [
377                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
378            ],
379            "syntax": "butt | round | square"
380        },
381        "stroke-linejoin": {
382            "comment": "added SVG property",
383            "references": [
384                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
385            ],
386            "syntax": "miter | round | bevel"
387        },
388        "stroke-miterlimit": {
389            "comment": "added SVG property (<miterlimit> = <number-one-or-greater>) ",
390            "references": [
391                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
392            ],
393            "syntax": "<number-one-or-greater>"
394        },
395        "stroke-opacity": {
396            "comment": "added SVG property",
397            "references": [
398                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
399            ],
400            "syntax": "<number-zero-one>"
401        },
402        "stroke-width": {
403            "comment": "added SVG property",
404            "references": [
405                "https://www.w3.org/TR/SVG/painting.html#StrokeProperties"
406            ],
407            "syntax": "<svg-length>"
408        },
409        "text-anchor": {
410            "comment": "added SVG property",
411            "references": [
412                "https://www.w3.org/TR/SVG/text.html#TextAlignmentProperties"
413            ],
414            "syntax": "start | middle | end"
415        },
416        "unicode-bidi": {
417            "comment": "added prefixed keywords https://developer.mozilla.org/en-US/docs/Web/CSS/unicode-bidi",
418            "syntax": "| -moz-isolate | -moz-isolate-override | -moz-plaintext | -webkit-isolate | -webkit-isolate-override | -webkit-plaintext"
419        },
420        "unicode-range": {
421            "comment": "added missed property https://developer.mozilla.org/en-US/docs/Web/CSS/%40font-face/unicode-range",
422            "syntax": "<urange>#"
423        },
424        "voice-balance": {
425            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
426            "syntax": "<number> | left | center | right | leftwards | rightwards"
427        },
428        "voice-duration": {
429            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
430            "syntax": "auto | <time>"
431        },
432        "voice-family": {
433            "comment": "<name> -> <family-name>, https://www.w3.org/TR/css3-speech/#property-index",
434            "syntax": "[ [ <family-name> | <generic-voice> ] , ]* [ <family-name> | <generic-voice> ] | preserve"
435        },
436        "voice-pitch": {
437            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
438            "syntax": "<frequency> && absolute | [ [ x-low | low | medium | high | x-high ] || [ <frequency> | <semitones> | <percentage> ] ]"
439        },
440        "voice-range": {
441            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
442            "syntax": "<frequency> && absolute | [ [ x-low | low | medium | high | x-high ] || [ <frequency> | <semitones> | <percentage> ] ]"
443        },
444        "voice-rate": {
445            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
446            "syntax": "[ normal | x-slow | slow | medium | fast | x-fast ] || <percentage>"
447        },
448        "voice-stress": {
449            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
450            "syntax": "normal | strong | moderate | none | reduced"
451        },
452        "voice-volume": {
453            "comment": "https://www.w3.org/TR/css3-speech/#property-index",
454            "syntax": "silent | [ [ x-soft | soft | medium | loud | x-loud ] || <decibel> ]"
455        },
456        "writing-mode": {
457            "comment": "extend with SVG keywords",
458            "syntax": "| <svg-writing-mode>"
459        }
460    },
461    "syntaxes": {
462        "-legacy-gradient": {
463            "comment": "added collection of legacy gradient syntaxes",
464            "syntax": "<-webkit-gradient()> | <-legacy-linear-gradient> | <-legacy-repeating-linear-gradient> | <-legacy-radial-gradient> | <-legacy-repeating-radial-gradient>"
465        },
466        "-legacy-linear-gradient": {
467            "comment": "like standard syntax but w/o `to` keyword https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient",
468            "syntax": "-moz-linear-gradient( <-legacy-linear-gradient-arguments> ) | -webkit-linear-gradient( <-legacy-linear-gradient-arguments> ) | -o-linear-gradient( <-legacy-linear-gradient-arguments> )"
469        },
470        "-legacy-repeating-linear-gradient": {
471            "comment": "like standard syntax but w/o `to` keyword https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient",
472            "syntax": "-moz-repeating-linear-gradient( <-legacy-linear-gradient-arguments> ) | -webkit-repeating-linear-gradient( <-legacy-linear-gradient-arguments> ) | -o-repeating-linear-gradient( <-legacy-linear-gradient-arguments> )"
473        },
474        "-legacy-linear-gradient-arguments": {
475            "comment": "like standard syntax but w/o `to` keyword https://developer.mozilla.org/en-US/docs/Web/CSS/linear-gradient",
476            "syntax": "[ <angle> | <side-or-corner> ]? , <color-stop-list>"
477        },
478        "-legacy-radial-gradient": {
479            "comment": "deprecated syntax that implemented by some browsers https://www.w3.org/TR/2011/WD-css3-images-20110908/#radial-gradients",
480            "syntax": "-moz-radial-gradient( <-legacy-radial-gradient-arguments> ) | -webkit-radial-gradient( <-legacy-radial-gradient-arguments> ) | -o-radial-gradient( <-legacy-radial-gradient-arguments> )"
481        },
482        "-legacy-repeating-radial-gradient": {
483            "comment": "deprecated syntax that implemented by some browsers https://www.w3.org/TR/2011/WD-css3-images-20110908/#radial-gradients",
484            "syntax": "-moz-repeating-radial-gradient( <-legacy-radial-gradient-arguments> ) | -webkit-repeating-radial-gradient( <-legacy-radial-gradient-arguments> ) | -o-repeating-radial-gradient( <-legacy-radial-gradient-arguments> )"
485        },
486        "-legacy-radial-gradient-arguments": {
487            "comment": "deprecated syntax that implemented by some browsers https://www.w3.org/TR/2011/WD-css3-images-20110908/#radial-gradients",
488            "syntax": "[ <position> , ]? [ [ [ <-legacy-radial-gradient-shape> || <-legacy-radial-gradient-size> ] | [ <length> | <percentage> ]{2} ] , ]? <color-stop-list>"
489        },
490        "-legacy-radial-gradient-size": {
491            "comment": "before a standard it contains 2 extra keywords (`contain` and `cover`) https://www.w3.org/TR/2011/WD-css3-images-20110908/#ltsize",
492            "syntax": "closest-side | closest-corner | farthest-side | farthest-corner | contain | cover"
493        },
494        "-legacy-radial-gradient-shape": {
495            "comment": "define to double sure it doesn't extends in future https://www.w3.org/TR/2011/WD-css3-images-20110908/#ltshape",
496            "syntax": "circle | ellipse"
497        },
498        "-non-standard-font": {
499            "comment": "non standard fonts",
500            "references": [
501                "https://webkit.org/blog/3709/using-the-system-font-in-web-content/"
502            ],
503            "syntax": "-apple-system-body | -apple-system-headline | -apple-system-subheadline | -apple-system-caption1 | -apple-system-caption2 | -apple-system-footnote | -apple-system-short-body | -apple-system-short-headline | -apple-system-short-subheadline | -apple-system-short-caption1 | -apple-system-short-footnote | -apple-system-tall-body"
504        },
505        "-non-standard-color": {
506            "comment": "non standard colors",
507            "references": [
508                "http://cssdot.ru/%D0%A1%D0%BF%D1%80%D0%B0%D0%B2%D0%BE%D1%87%D0%BD%D0%B8%D0%BA_CSS/color-i305.html",
509                "https://developer.mozilla.org/en-US/docs/Web/CSS/color_value#Mozilla_Color_Preference_Extensions"
510            ],
511            "syntax": "-moz-ButtonDefault | -moz-ButtonHoverFace | -moz-ButtonHoverText | -moz-CellHighlight | -moz-CellHighlightText | -moz-Combobox | -moz-ComboboxText | -moz-Dialog | -moz-DialogText | -moz-dragtargetzone | -moz-EvenTreeRow | -moz-Field | -moz-FieldText | -moz-html-CellHighlight | -moz-html-CellHighlightText | -moz-mac-accentdarkestshadow | -moz-mac-accentdarkshadow | -moz-mac-accentface | -moz-mac-accentlightesthighlight | -moz-mac-accentlightshadow | -moz-mac-accentregularhighlight | -moz-mac-accentregularshadow | -moz-mac-chrome-active | -moz-mac-chrome-inactive | -moz-mac-focusring | -moz-mac-menuselect | -moz-mac-menushadow | -moz-mac-menutextselect | -moz-MenuHover | -moz-MenuHoverText | -moz-MenuBarText | -moz-MenuBarHoverText | -moz-nativehyperlinktext | -moz-OddTreeRow | -moz-win-communicationstext | -moz-win-mediatext | -moz-activehyperlinktext | -moz-default-background-color | -moz-default-color | -moz-hyperlinktext | -moz-visitedhyperlinktext | -webkit-activelink | -webkit-focus-ring-color | -webkit-link | -webkit-text"
512        },
513        "-non-standard-image-rendering": {
514            "comment": "non-standard keywords http://phrogz.net/tmp/canvas_image_zoom.html",
515            "syntax": "optimize-contrast | -moz-crisp-edges | -o-crisp-edges | -webkit-optimize-contrast"
516        },
517        "-non-standard-overflow": {
518            "comment": "non-standard keywords https://developer.mozilla.org/en-US/docs/Web/CSS/overflow",
519            "syntax": "-moz-scrollbars-none | -moz-scrollbars-horizontal | -moz-scrollbars-vertical | -moz-hidden-unscrollable"
520        },
521        "-non-standard-width": {
522            "comment": "non-standard keywords https://developer.mozilla.org/en-US/docs/Web/CSS/width",
523            "syntax": "fill-available | min-intrinsic | intrinsic | -moz-available | -moz-fit-content | -moz-min-content | -moz-max-content | -webkit-min-content | -webkit-max-content"
524        },
525        "-webkit-gradient()": {
526            "comment": "first Apple proposal gradient syntax https://webkit.org/blog/175/introducing-css-gradients/ - TODO: simplify when after match algorithm improvement ( [, point, radius | , point] -> [, radius]? , point )",
527            "syntax": "-webkit-gradient( <-webkit-gradient-type>, <-webkit-gradient-point> [, <-webkit-gradient-point> | , <-webkit-gradient-radius>, <-webkit-gradient-point> ] [, <-webkit-gradient-radius>]? [, <-webkit-gradient-color-stop>]* )"
528        },
529        "-webkit-gradient-color-stop": {
530            "comment": "first Apple proposal gradient syntax https://webkit.org/blog/175/introducing-css-gradients/",
531            "syntax": "from( <color> ) | color-stop( [ <number-zero-one> | <percentage> ] , <color> ) | to( <color> )"
532        },
533        "-webkit-gradient-point": {
534            "comment": "first Apple proposal gradient syntax https://webkit.org/blog/175/introducing-css-gradients/",
535            "syntax": "[ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ]"
536        },
537        "-webkit-gradient-radius": {
538            "comment": "first Apple proposal gradient syntax https://webkit.org/blog/175/introducing-css-gradients/",
539            "syntax": "<length> | <percentage>"
540        },
541        "-webkit-gradient-type": {
542            "comment": "first Apple proposal gradient syntax https://webkit.org/blog/175/introducing-css-gradients/",
543            "syntax": "linear | radial"
544        },
545        "-webkit-mask-box-repeat": {
546            "comment": "missed; https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-mask-box-image",
547            "syntax": "repeat | stretch | round"
548        },
549        "-webkit-mask-clip-style": {
550            "comment": "missed; there is no enough information about `-webkit-mask-clip` property, but looks like all those keywords are working",
551            "syntax": "border | border-box | padding | padding-box | content | content-box | text"
552        },
553        "-ms-filter-function-list": {
554            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/-ms-filter",
555            "syntax": "<-ms-filter-function>+"
556        },
557        "-ms-filter-function": {
558            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/-ms-filter",
559            "syntax": "<-ms-filter-function-progid> | <-ms-filter-function-legacy>"
560        },
561        "-ms-filter-function-progid": {
562            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/-ms-filter",
563            "syntax": "'progid:' [ <ident-token> '.' ]* [ <ident-token> | <function-token> <any-value>? ) ]"
564        },
565        "-ms-filter-function-legacy": {
566            "comment": "https://developer.mozilla.org/en-US/docs/Web/CSS/-ms-filter",
567            "syntax": "<ident-token> | <function-token> <any-value>? )"
568        },
569        "-ms-filter": {
570            "syntax": "<string>"
571        },
572        "age": {
573            "comment": "https://www.w3.org/TR/css3-speech/#voice-family",
574            "syntax": "child | young | old"
575        },
576        "attr-name": {
577            "syntax": "<wq-name>"
578        },
579        "attr-fallback": {
580            "syntax": "<any-value>"
581        },
582        "border-radius": {
583            "comment": "missed, https://drafts.csswg.org/css-backgrounds-3/#the-border-radius",
584            "syntax": "<length-percentage>{1,2}"
585        },
586        "bottom": {
587            "comment": "missed; not sure we should add it, but no others except `shape` is using it so it's ok for now; https://drafts.fxtf.org/css-masking-1/#funcdef-clip-rect",
588            "syntax": "<length> | auto"
589        },
590        "content-list": {
591            "comment": "missed -> https://drafts.csswg.org/css-content/#typedef-content-list (document-url, <target> and leader() is omitted util stabilization)",
592            "syntax": "[ <string> | contents | <image> | <quote> | <target> | <leader()> | <attr()> | counter( <ident>, <'list-style-type'>? ) ]+"
593        },
594        "element()": {
595            "comment": "https://drafts.csswg.org/css-gcpm/#element-syntax & https://drafts.csswg.org/css-images-4/#element-notation",
596            "syntax": "element( <custom-ident> , [ first | start | last | first-except ]? ) | element( <id-selector> )"
597        },
598        "generic-voice": {
599            "comment": "https://www.w3.org/TR/css3-speech/#voice-family",
600            "syntax": "[ <age>? <gender> <integer>? ]"
601        },
602        "gender": {
603            "comment": "https://www.w3.org/TR/css3-speech/#voice-family",
604            "syntax": "male | female | neutral"
605        },
606        "generic-family": {
607            "comment": "added -apple-system",
608            "references": [
609                "https://webkit.org/blog/3709/using-the-system-font-in-web-content/"
610            ],
611            "syntax": "| -apple-system"
612        },
613        "gradient": {
614            "comment": "added legacy syntaxes support",
615            "syntax": "| <-legacy-gradient>"
616        },
617        "left": {
618            "comment": "missed; not sure we should add it, but no others except `shape` is using it so it's ok for now; https://drafts.fxtf.org/css-masking-1/#funcdef-clip-rect",
619            "syntax": "<length> | auto"
620        },
621        "mask-image": {
622            "comment": "missed; https://drafts.fxtf.org/css-masking-1/#the-mask-image",
623            "syntax": "<mask-reference>#"
624        },
625        "name-repeat": {
626            "comment": "missed, and looks like obsolete, keep it as is since other property syntaxes should be changed too; https://www.w3.org/TR/2015/WD-css-grid-1-20150917/#typedef-name-repeat",
627            "syntax": "repeat( [ <positive-integer> | auto-fill ], <line-names>+)"
628        },
629        "named-color": {
630            "comment": "added non standard color names",
631            "syntax": "| <-non-standard-color>"
632        },
633        "paint": {
634            "comment": "used by SVG https://www.w3.org/TR/SVG/painting.html#SpecifyingPaint",
635            "syntax": "none | <color> | <url> [ none | <color> ]? | context-fill | context-stroke"
636        },
637        "page-size": {
638            "comment": "https://www.w3.org/TR/css-page-3/#typedef-page-size-page-size",
639            "syntax": "A5 | A4 | A3 | B5 | B4 | JIS-B5 | JIS-B4 | letter | legal | ledger"
640        },
641        "ratio": {
642            "comment": "missed, https://drafts.csswg.org/mediaqueries-4/#typedef-ratio",
643            "syntax": "<integer> / <integer>"
644        },
645        "right": {
646            "comment": "missed; not sure we should add it, but no others except `shape` is using it so it's ok for now; https://drafts.fxtf.org/css-masking-1/#funcdef-clip-rect",
647            "syntax": "<length> | auto"
648        },
649        "shape": {
650            "comment": "missed spaces in function body and add backwards compatible syntax",
651            "syntax": "rect( <top>, <right>, <bottom>, <left> ) | rect( <top> <right> <bottom> <left> )"
652        },
653        "svg-length": {
654            "comment": "All coordinates and lengths in SVG can be specified with or without a unit identifier",
655            "references": [
656                "https://www.w3.org/TR/SVG11/coords.html#Units"
657            ],
658            "syntax": "<percentage> | <length> | <number>"
659        },
660        "svg-writing-mode": {
661            "comment": "SVG specific keywords (deprecated for CSS)",
662            "references": [
663                "https://developer.mozilla.org/en/docs/Web/CSS/writing-mode",
664                "https://www.w3.org/TR/SVG/text.html#WritingModeProperty"
665            ],
666            "syntax": "lr-tb | rl-tb | tb-rl | lr | rl | tb"
667        },
668        "top": {
669            "comment": "missed; not sure we should add it, but no others except `shape` is using it so it's ok for now; https://drafts.fxtf.org/css-masking-1/#funcdef-clip-rect",
670            "syntax": "<length> | auto"
671        },
672        "track-group": {
673            "comment": "used by old grid-columns and grid-rows syntax v0",
674            "syntax": "'(' [ <string>* <track-minmax> <string>* ]+ ')' [ '[' <positive-integer> ']' ]? | <track-minmax>"
675        },
676        "track-list-v0": {
677            "comment": "used by old grid-columns and grid-rows syntax v0",
678            "syntax": "[ <string>* <track-group> <string>* ]+ | none"
679        },
680        "track-minmax": {
681            "comment": "used by old grid-columns and grid-rows syntax v0",
682            "syntax": "minmax( <track-breadth> , <track-breadth> ) | auto | <track-breadth> | fit-content"
683        },
684        "x": {
685            "comment": "missed; not sure we should add it, but no others except `cursor` is using it so it's ok for now; https://drafts.csswg.org/css-ui-3/#cursor",
686            "syntax": "<number>"
687        },
688        "y": {
689            "comment": "missed; not sure we should add it, but no others except `cursor` is using so it's ok for now; https://drafts.csswg.org/css-ui-3/#cursor",
690            "syntax": "<number>"
691        },
692        "declaration": {
693            "comment": "missed, restored by https://drafts.csswg.org/css-syntax",
694            "syntax": "<ident-token> : <declaration-value>? [ '!' important ]?"
695        },
696        "declaration-list": {
697            "comment": "missed, restored by https://drafts.csswg.org/css-syntax",
698            "syntax": "[ <declaration>? ';' ]* <declaration>?"
699        },
700        "url": {
701            "comment": "https://drafts.csswg.org/css-values-4/#urls",
702            "syntax": "url( <string> <url-modifier>* ) | <url-token>"
703        },
704        "url-modifier": {
705            "comment": "https://drafts.csswg.org/css-values-4/#typedef-url-modifier",
706            "syntax": "<ident> | <function-token> <any-value> )"
707        },
708        "number-zero-one": {
709            "syntax": "<number [0,1]>"
710        },
711        "number-one-or-greater": {
712            "syntax": "<number [1,∞]>"
713        },
714        "positive-integer": {
715            "syntax": "<integer [0,∞]>"
716        },
717        "-non-standard-display": {
718            "syntax": "-ms-inline-flexbox | -ms-grid | -ms-inline-grid | -webkit-flex | -webkit-inline-flex | -webkit-box | -webkit-inline-box | -moz-inline-stack | -moz-box | -moz-inline-box"
719        }
720    }
721}
722