CSS Checker Flags (tick_24Pro, tick_24Std, cross_24Lite)

Quick jump to flag: 600 | 601 | 602 | 603 | 604 | 605 | 606 | 607 | 608 | 609 | 610 | 611 | 612 | 613 | 614

For the validator flags, see the Validator Flag Descriptions topic.

CSS Checker Flags

These flags function similarly to the tag name program flags. You can disable or enable them as you wish. To avoid confusion with the tag name program flags and for other design reasons, the style checker flags start at 600.

Flag 600 (Internet Explorer specific messages)

If the "hand" generic cursor value is used with the "cursor" CSS property, displays a message that it is Internet Explorer specific.

If the "background-position-x" or "background-position-y" CSS property is used, displays a message that they are Internet Explorer 4.0+ specific and recommends the use of the "background-position" property instead.

If the "behavior" CSS property is used, displays a message that it is Internet Explorer 5.0+ specific.

If the "layout-flow" CSS property is used, displays a message that it is Internet Explorer specific and is deprecated. (New v14.0016)

If the "layout-grid" CSS properties are used, displays a message that they are Internet Explorer 5.0+ specific.

If the "line-break" CSS property is used, displays a message that it is Internet Explorer 5.0+ specific.

If the "scrollbar" CSS properties are used, displays a message that they are Internet Explorer 5.5+ specific.

If the "text-autospace" CSS property is used, displays a message that it is Internet Explorer 5.0+ specific.

If the "text-kashida-space" CSS property is used, displays a message that it is Internet Explorer 6.0+ specific.

If the "text-overflow" CSS property is used, displays a message that it is Internet Explorer 6.0+ specific.

If the "text-underline-position" CSS property is used, displays a message that it is Internet Explorer 5.5+ specific.

If the "writing-mode" CSS property is used, displays a message that it is Internet Explorer 5.5+ specific.

If the "zoom" CSS property is used, displays a message that it is Internet Explorer 5.5+ specific.

Flag 601 (General compatibility messages)

If a custom cursor is specified for a "cursor" CSS property, displays a message that custom cursors are not widely supported.

If the "background-attachment" or "background-position" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "border-bottom", "border-left", "border-right", or "border-top" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "border-bottom-width", "border-left-width", "border-right-width", or "border-top-width" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "font-variant" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "height" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "letter-spacing" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "list-style-image" or "list-style-position" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "overflow-x" or "overflow-y" CSS property is used, displays a message that these are not standard CSS1 or CSS 2.1 properties (but are CSS3 properties), but most values are supported by Internet Explorer 4.0+; also recommends the use of the "overflow" property instead, which is a standard CSS 2.1 property.

If the "vertical-align" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "word-spacing" CSS property is used, displays a message that it is supported by Internet Explorer 6.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

Flag 602 (Netscape specific messages)

If the "count-down", "count-up", "count-up-down", or "spinning" generic cursor value is used with the "cursor" CSS property, displays a warning message that these values are Netscape 6.0+ specific.

If the "layer-background-color" or "layer-background-image" CSS property is used, displays a message that these properties are specific to older versions of Netscape like Netscape v4.x. (New v8.01)

Flag 603 (More general compatibility messages)

These messages are displayed for CSS2 properties that are not also CSS1 properties. It is likely that these CSS2 properties are less well-supported than CSS1 properties.

If an outline CSS property is used (like "outline", "outline-color", "outline-style", "outline-width"), displays a message that it is not supported by older browsers.

If the "border-bottom-color", "border-left-color", "border-right-color", or "border-top-color" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "border-bottom-style", "border-left-style", "border-right-style", or "border-top-style" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 3.5+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "border-collapse" CSS property is used, displays a message that it is supported by Internet Explorer 5.0+ and Opera 4.0+ but not by Internet Explorer 4.0- and Netscape 6.2-. NOTE: Flag 114 must be unchecked for this message to display.

If the "border-image" CSS property is used, displays a warning message that CSS3 border images are supported by all major browsers except IE9 and below. (New v11.01)

If the "border-spacing" CSS property is used, displays a message that it is supported by Netscape 6.0+ and Opera 4.0+ but not by Internet Explorer 6.0- and Netscape 4.x-.

If the "bottom" CSS property is used, displays a message that it is supported by Internet Explorer 5.0+, Netscape 6.0+, and Opera 4.0+ but not by Internet Explorer 4.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "caption-side" CSS property is used, displays a message that it is supported by Netscape 6.0+ and Opera 4.0+ but not by Internet Explorer 6.0- and Netscape 4.x-.

If the "content" CSS property is used, displays a message that it is supported by Netscape 6.0+ and Opera 4.0+ but not by Internet Explorer 6.0- and Netscape 4.x-.

If the "counter-increment" or "counter-reset" CSS property is used, displays a message that it is not supported by Internet Explorer 7.0 and below.

If the "cursor" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+ and Netscape 6.0+ but not by Netscape 4.x- and Opera 6.0-. NOTE: Flag 114 must be unchecked for this message to display.

If the "empty-cells" CSS property is used, displays a message that it is supported by modern browsers (but support may be buggy) but not by Internet Explorer 7.0-.

If the "left" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 4.0+, and Opera 4.0+. NOTE: Flag 114 must be unchecked for this message to display.

If the "min-height" or "max-height" CSS property is used, displays a message that it is supported by Firefox 1+, IE 7+, Netscape 6.0+ and Opera 4.0+ but not by Internet Explorer 6.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "min-width" or "max-width" CSS property is used, displays a message that it is supported by Firefox 1+, IE 7+, Netscape 6.0+ and Opera 4.0+ but not by Internet Explorer 6.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "orphans" or "widows" CSS property is used, displays a warning message about its limited support.

If the "overflow" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 6.0+, and Opera 4.0+ but not by Internet Explorer 3.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "page-break-after" or "page-break-before" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+ and Opera 3.5+ but not by Netscape 6.2-. NOTE: Flag 114 must be unchecked for this message to display.

If the "page-break-inside" CSS property is used, displays a message that it is supported by Chrome 1.0+, Firefox 19+, Internet Explorer 8.0+, Opera 3.5+, and Safari 1.3+, but not by Firefox 18- and Internet Explorer 7.0-.

If the "position" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 4.0+, and Opera 4.0+. NOTE: Flag 114 must be unchecked for this message to display.

If the "quotes" CSS property is used, displays a message that it is supported by Chrome 11+, Firefox 1.5+, Internet Explorer 8.0+, and Opera 4.0+, but not by Internet Explorer 7.0-.

If the "right" CSS property is used, displays a message that it is supported by Internet Explorer 5.0+, Netscape 6.0+, and Opera 4.0+ but not by Internet Explorer 4.0- and Netscape 4.x-. NOTE: Flag 114 must be unchecked for this message to display.

If the "table-layout" CSS property is used, displays a message that it is supported by Internet Explorer 5.0+ and Netscape 6.0+ but not by Netscape 4.x- and Opera 6.0-. NOTE: Flag 114 must be unchecked for this message to display.

If the "top" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 4.0+, and Opera 4.0+. NOTE: Flag 114 must be unchecked for this message to display.

If the "visibility" CSS property is used, displays a message that it is supported by Internet Explorer 4.0+, Netscape 4.0+, and Opera 4.0+. NOTE: Flag 114 must be unchecked for this message to display.

Flag 604

Displays a message if the "border-width", "border-style", or "border-color" property is used with the shorthand "border" property.

Displays a message if the "border-bottom-width", "border-bottom-style", or "border-bottom-color" property is used with the shorthand "border-bottom" property.

Also displays similar messages for the "border-left", "border-right", and "border-top" shorthand properties.

Flag 605 (New CSS3 property messages)

These messages are displayed for CSS3 properties and values that are not also CSS2 properties or values. It is likely that these CSS3 properties and values are less well-supported than CSS2 properties and values.

If the "align-content", "align-items", or "align-self" flexbox property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If the "all" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If the "appearance" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If the "background-clip" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If the "background-origin" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If the "background-size" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "border-image" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "border-radius", "border-top-right-radius", "border-bottom-right-radius", "border-bottom-left-radius", or "border-top-left-radius" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "box-sizing" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If any "break-*" CSS property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "column" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If any "flex-*" flexbox property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If the "hanging-punctuation" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "icon" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "justify-content" flexbox property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If any "mark" speech property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "marks" or "size" CSS property is used, displays a message that these properties are CSS3 properties but not CSS 2.1 properties and are not yet widely supported. (New v15.00)

If any "marquee-*" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If any "nav-*" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "opacity" CSS property is used, displays a message that it is a CSS3 property with information about its support in various browsers as well as information about IE's "alpha filters" and the older "-moz-opacity" property. (New v9.02)

If the "order" flexbox property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If the "outline-offset" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "overflow-*" CSS property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If the "punctuation-trim" CSS property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If the "resize" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "rest" speech property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If any "ruby-*" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "speak-*" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "text-align-last" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support (but most values are supported by IE 5.5+). (New v9.99)

If the "text-emphasis" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support (but most values are supported by IE 5.5+). (New v9.99)

If the "text-justify" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support (but most values are supported by IE 5.0+). (New v9.99)

If the "text-wrap" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v9.99)

If any "voice-*" property is used, displays a message that these properties are CSS3 properties but not CSS1 or CSS 2.1 properties and may have limited support. (New v9.99)

If the "will-change" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support. (New v15.00)

If the "word-break" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support (but most values are supported by IE 5.0+). (New v9.99)

If the "word-wrap" property is used, displays a message that it is a CSS3 property but not a CSS1 or CSS 2.1 property and may have limited support (but is supported by IE 5.5+). (New v9.99)

Flag 606 (CSS3 multiple images messages)

If the "background" property is used and it specifies multiple background layers, displays a message that it is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-attachment" property is used and it specifies attachments for multiple images, displays a message that it is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-image" property is used and it specifies multiple images, displays a message that it is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-repeat" property is used and it specifies how images are tiled for multiple images, displays a message that it is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

Flag 607

Displays a warning message if the "margin-bottom", "margin-left", "margin-right", or "margin-top" property is used with the "margin" shorthand property.

Displays a warning message if the "padding-bottom", "padding-left", "padding-right", or "padding-top" property is used with the "padding" shorthand property.

Flag 608 (CSS 2.1 related messages)

If an "@font-face" declaration is made, displays a warning message that it's been removed from CSS 2.1 due to poor support and its use is not recommended.

If the "aural" media type is used, displays a warning message that it's deprecated (and removed) in CSS 2.1 in favor of the "speech" media type and its use is not recommended.

If the "left" or "right" value is used with the "caption-side" CSS property, displays a warning message that it's been removed from CSS 2.1 due to poor support and its use is not recommended.

If the "compact" value is used with the "display" CSS property, displays a warning message that it's been removed from CSS 2.1 (but is back in CSS3) due to poor support and may have limited browser support.

If the "marker" value is used with the "display" CSS property, displays a warning message that it's been removed from CSS 2.1 and CSS3 due to poor support and its use is not recommended.

If the "hebrew", "cjk-ideographic", "hiragana", "katakana", "hiragana-iroha", or "katakana-iroha" value is used with the "list-style-type" CSS property, displays a warning message that it's been removed from CSS 2.1 due to poor support and its use is not recommended.

If the "marker-offset" CSS property is used, displays a warning message that it's been removed from CSS 2.1 due to poor support and its use is not recommended.

Flag 609 (CSS3 deprecation related messages)

This flag is no longer in use in v15.00+. The single message that was controlled by this flag is now controlled by message ID.

Flag 610 (CSS3 values)

If the "background" property uses a CSS3 value that does not appear to also be a valid CSS2 value, displays a message that the value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-attachment" or "background" property uses the "local" value, displays a message that it is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-position" or "background" property uses a CSS3 <bg-position> value that is not also a valid CSS 2.1 value, displays a message that the value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "background-repeat" or "background" property uses the "space" or "round" values, displays a message that these values are allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If any "cue" property uses a CSS3 value that is not also a valid CSS 2.1 value, displays a message that the value is allowed by CSS3 but not by CSS 2.1, and may have limited support. (New v9.99)

If the "cursor" property specifies optional <x> and <y> coordinates after a <uri>, displays a message that it is allowed by CSS3 but not by previous CSS versions and may have limited support. (New v9.99)

If the "cursor" property uses a CSS3 generic cursor keyword, displays a message that it is allowed by CSS3 but not by previous CSS versions and may have limited support. (New v9.99)

If the "display" property uses any ruby values, displays a warning message that it is allowed by CSS3 but not by previous CSS versions and may have limited support. (New v9.99)

If the "display" property uses a template value, displays a message that it is allowed by CSS3 but not by previous CSS versions and may have limited support. (New v9.99)

If the "currentColor" color value is used, displays a message that it is allowed by CSS3 but not by previous CSS versions and is not supported in IE8 and below. (New v9.99)

If the "font" property uses a CSS3 value that is not also a valid CSS 2.1 value, displays a message that the value is allowed by CSS3 but not by CSS 2.1, and may have limited support. (New v9.99)

If an "hsl()", or "hsla()" color value is used, displays a message about its support in current browsers but not in IE8 and below. (New v9.99)

If the "letter-spacing" property has a percent value or has more than one value, displays a message that this value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "outline-style" property uses the "auto" value, displays a message that this value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If any "pause" property uses a CSS3 value that is not also a valid CSS 2.1 value, displays a message that the value is allowed by CSS3 but not by CSS 2.1, and may have limited support. (New v9.99)

If the "position" property uses a template value, displays a message that it is allowed by CSS3 but not by previous CSS versions and may have limited support. (New v9.99)

If an "rgba()" color value is used, displays a message about its limited support, including not being supported by IE8. (New v9.99)

If the "text-indent" property uses the "hanging" value, displays a message that this value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

If the "transparent" color value is used, displays a message that it is allowed by CSS3 but not by previous CSS versions and is not fully supported in IE8 and below. (New v9.99)

If the "unicode-bidi" property uses a CSS3 value that is not also a valid CSS 2.1 value, displays a message that the value is allowed by CSS3 but not by CSS 2.1, and may have limited support. (New v15.00)

If the "word-spacing" property has a percent value, displays a message that this value is allowed by CSS3 but not by previous CSS versions, and may have limited support. (New v9.99)

Flag 611 (Proprietary property messages)

This flag displays messages for known and unknown proprietary CSS properties, like "-ms-" properties for Internet Explorer, "-moz-" properties for Mozilla/Firefox, "-o-" properties for Opera, "-webkit-" properties for Safari/WebKit, "-khtml-" properties for the Konqueror browser, and other proprietary properties that start with "-". (New v11.01)

If you understand that vendor specific properties (properties that have vendor specific prefixes) are specific to certain browsers, and you don't want to be alerted to them with a message, then you may want to uncheck or disable this flag to reduce 'clutter'.

Flag 612 (Duplicate Property Definitions)

This flag enables messages about duplicate property definitions in style blocks. If you are purposely using duplicate property definitions to take advantage of cascading or for better backwards compatibility, then you may want to disable this flag. (New v11.01)

Flag 613 (New CSS4 property messages)

Displays messages for CSS4 properties and values that are not also CSS3 properties or values. It is likely that these CSS4 properties and values are less well-supported than CSS3 properties and values.

Displays messages for these new CSS4 properties (may not be a complete list): "color-adjust" (New v15.00), "color-correction" (New v15.00), "image-rendering" (New v14.0015), "touch-action" (New v14.03)

Flag 614 (CSS4 values)

If the "image-orientation" property uses a CSS4 value that does not appear to also be a valid CSS3 value, displays a message that the value is allowed by CSS4 but not by previous CSS versions, and may have limited support. (New v15.00)