Non-standard and Obsolete CSS Properties

bad_css

OBSOLETE PREFIXES
    -xv-interpret-as      // -xv- and -o- are old Opera prefixes for the Presto
    -xv-phonemes          // engine. Opera switched to the Blink engine with
    -xv-voice-balance     // version 15. The current version is 34.
    -xv-voice-duration
    -xv-voice-pitch
    -xv-voice-pitch-range
    -xv-voice-rate
    -xv-voice-stress
    -xv-voice-volume
    -o-border-image
    -o-device-pixel-ratio
    -o-focus-opacity
    -o-link
    -o-link-source
    -o-mini-fold
    -o-object-fit
    -o-object-position
    -o-tab-size
    -o-table-baseline
    -o-transform
    -o-transform-origin
    -o-transition
    -o-transition-delay
    -o-transition-duration
    -o-transition-property
    -o-transition-timing-function
    -apple-dashboard-region   // use -webkit- instead of -apple-. non-standard anyway.
    -wap-accesskey            // -wap- was part of the failed Wireless CSS spec. WCSS 
    -wap-input-format         // was a subset of CSS2 with a few extensions.
    -wap-input-required       // -wap- prefixed properties should not be used.
    -wap-marquee-dir
    -wap-marquee-loop
    -wap-marquee-speed
    -wap-marquee-style

OBSOLETE PROPERTIES
    -ms-flex-align            // IE10 supports the old 2012 syntax. IE11 supports
    -ms-flex-item-align       // the modern syntax unprefixed. 
    -ms-flex-line-pack
    -ms-flex-negative
    -ms-flex-order
    -ms-flex-pack
    -ms-flex-positive
    -ms-flex-preferred-size
    clip
    -webkit-mask-source-type  // i think this was renamed to mask-type

NO NEED FOR PREFIX
    -moz-animation            // CSS3 animations were unprefixed in Firefox 15. the
    -moz-animation-delay      // current version is 43
    -moz-animation-direction
    -moz-animation-duration
    -moz-animation-fill-mode
    -moz-animation-iteration-count
    -moz-animation-name
    -moz-animation-play-state
    -moz-animation-timing-function
    -moz-backface-visibility  // unprefixed in Firefox 16
    -moz-border-image         // unprefixed in Firefox 15
    -moz-perspective          // unprefixed in Firefox 16
    -moz-perspective-origin   // unprefixed in Firefox 16
    -moz-transform            // unprefixed in Firefox 16
    -moz-transform-origin     // unprefixed in Firefox 16
    -moz-transform-style      // unprefixed in Firefox 16
    -moz-transition           // unprefixed in Firefox 16
    -moz-transition-delay     // unprefixed in Firefox 16
    -moz-transition-duration  // unprefixed in Firefox 16
    -moz-transition-property  // unprefixed in Firefox 16
    -moz-transition-timing-function  // unprefixed in Firefox 16
    -ms-animation             // unprefixed in IE10. according to caniuse.com,
    -ms-animation-delay       // animation properties were never prefixed
    -ms-animation-direction
    -ms-animation-duration
    -ms-animation-fill-mode
    -ms-animation-iteration-count
    -ms-animation-name
    -ms-animation-play-state
    -ms-animation-timing-function
    -ms-font-feature-settings  // unprefixed in IE10. according to caniuse.com, this was never prefixed
    -ms-transition             // unprefixed in IE10. according to caniuse.com, these were never prefixed
    -ms-transition-delay
    -ms-transition-duration
    -ms-transition-property
    -ms-transition-timing-function
    -webkit-background-clip
    -webkit-background-origin
    -webkit-background-size
    -webkit-border-bottom-left-radius
    -webkit-border-bottom-right-radius
    -webkit-border-top-left-radius
    -webkit-border-top-right-radius
    -webkit-border-radius
    -webkit-box-sizing
    -webkit-opacity
    -webkit-text-decoration

NOT ON STANDARDS TRACK
    -epub-text-combine            // most of these are listed on MDN as "do not use",
    -webkit-text-combine          // but MDN has lots of errors.
    -webkit-dashboard-region
    -moz-background-inline-policy
    -moz-binding
    -moz-border-end
    -moz-border-end-color
    -moz-border-end-style
    -moz-border-end-width
    -moz-border-bottom-colors     // border-bottom-color is supported
    -moz-border-left-colors
    -moz-border-right-colors
    -moz-border-top-colors
    -moz-border-start
    -moz-border-start-color
    -moz-border-start-style
    -moz-border-start-width
    -moz-box-align
    -moz-box-direction
    -moz-box-flex
    -moz-box-ordinal-group
    -moz-box-orient
    -moz-box-pack
    -moz-control-character-visibility
    -moz-float-edge
    -moz-force-broken-image-icon
    -moz-image-region
    -moz-margin-end
    -moz-margin-start
    -moz-math-display
    -moz-math-variant
    -moz-orient
    -moz-osx-font-smoothing
    -moz-outline-radius
    -moz-outline-radius-bottomleft
    -moz-outline-radius-bottomright
    -moz-outline-radius-topleft
    -moz-outline-radius-topright
    -moz-padding-end
    -moz-padding-start
    -moz-script-level
    -moz-script-min-size
    -moz-script-size-multiplier
    -moz-stack-sizing
    -moz-user-focus
    -moz-user-input
    -moz-user-modify
    -moz-window-shadow
    -ms-block-progression
    -ms-content-zoom-chaining
    -ms-content-zoom-limit
    -ms-content-zoom-limit-max
    -ms-content-zoom-limit-min
    -ms-content-zoom-snap
    -ms-content-zoom-snap-points
    -ms-content-zoom-snap-type
    -ms-content-zooming
    -ms-grid-columns
    -ms-grid-rows
    -ms-high-contrast-adjust
    -ms-hyphenate-limit-chars
    -ms-hyphenate-limit-lines
    -ms-hyphenate-limit-zone
    -ms-ime-align
    -ms-interpolation-mode
    -ms-scroll-chaining
    -ms-scroll-limit
    -ms-scroll-limit-x-max
    -ms-scroll-limit-x-min
    -ms-scroll-limit-y-max
    -ms-scroll-limit-y-min
    -ms-scroll-rails
    -ms-scroll-snap-points-x
    -ms-scroll-snap-points-y
    -ms-scroll-snap-type
    -ms-scroll-snap-x
    -ms-scroll-snap-y
    -ms-scroll-translation
    -ms-text-combine-horizontal
    -ms-touch-action
    -ms-touch-select
    -ms-wrap-margin
    -webkit-aspect-ratio
    -webkit-background-composite
    -webkit-border-after
    -webkit-border-after-color
    -webkit-border-after-style
    -webkit-border-after-width
    -webkit-border-before
    -webkit-border-before-color
    -webkit-border-before-style
    -webkit-border-before-width
    -webkit-border-end
    -webkit-border-end-color
    -webkit-border-end-style
    -webkit-border-end-width
    -webkit-border-fit
    -webkit-border-horizontal-spacing
    -webkit-border-start
    -webkit-border-start-color
    -webkit-border-start-style
    -webkit-border-start-width
    -webkit-border-vertical-spacing
    -webkit-box-align
    -webkit-box-direction
    -webkit-box-flex
    -webkit-box-flex-group
    -webkit-box-lines
    -webkit-box-ordinal-group
    -webkit-box-orient
    -webkit-box-pack
    -webkit-box-reflect
    -webkit-box-shadow
    -webkit-column-axis
    -webkit-column-break-after
    -webkit-column-break-before
    -webkit-column-break-inside
    -webkit-alt
    -webkit-app-region
    -webkit-column-progression
    -webkit-font-smoothing
    -webkit-highlight
    -webkit-hyphenate-character
    -webkit-line-box-contain
    -webkit-line-break
    -webkit-line-clamp
    -webkit-locale
    -webkit-logical-height
    -webkit-logical-width
    -webkit-margin-after
    -webkit-margin-after-collapse
    -webkit-margin-before
    -webkit-margin-before-collapse
    -webkit-margin-bottom-collapse
    -webkit-margin-collapse
    -webkit-margin-end
    -webkit-margin-start
    -webkit-margin-top-collapse
    -webkit-marquee
    -webkit-marquee-direction
    -webkit-marquee-increment
    -webkit-marquee-repetition
    -webkit-marquee-speed
    -webkit-marquee-style
    -webkit-mask-box-image          // syntax was changed to mask-border-*
    -webkit-mask-box-image-outset
    -webkit-mask-box-image-repeat
    -webkit-mask-box-image-slice
    -webkit-mask-box-image-source
    -webkit-mask-box-image-width
    -webkit-mask-position-x
    -webkit-mask-position-y
    -webkit-mask-repeat-x
    -webkit-mask-repeat-y
    -webkit-max-logical-height
    -webkit-max-logical-width
    -webkit-min-logical-height
    -webkit-min-logical-width
    -webkit-padding-after
    -webkit-padding-before
    -webkit-padding-end
    -webkit-padding-start
    -webkit-perspective-origin-x
    -webkit-perspective-origin-y
    -webkit-print-color-adjust
    -webkit-region-break-after
    -webkit-region-break-before
    -webkit-region-break-inside
    -webkit-rtl-ordering
    -webkit-scroll-snap-coordinate
    -webkit-scroll-snap-destination
    -webkit-scroll-snap-points-x
    -webkit-scroll-snap-points-y
    -webkit-scroll-snap-type
    -webkit-svg-shadow
    -webkit-tap-highlight-color
    -webkit-text-decorations-in-effect
    -webkit-text-fill-color
    -webkit-text-security
    -webkit-text-stroke
    -webkit-text-stroke-color
    -webkit-text-stroke-width
    -webkit-touch-callout
    -webkit-transform-origin-x
    -webkit-transform-origin-y
    -webkit-transform-origin-z
    -webkit-user-drag
    -webkit-user-modify
    accelerator
    background-blend-mode
    background-repeat-x
    background-repeat-y
    buffered-rendering
    color-rendering
    enable-background
    fill
    fill-opacity
    fill-rule
    glyph-orientation-horizontal
    glyph-orientation-vertical
    kerning
    layout-flow
    layout-grid
    layout-grid-char
    layout-grid-line
    layout-grid-mode
    layout-grid-type
    marker
    marker-end
    marker-mid
    marker-offset
    marker-start
    paint-order
    ruby-overhang
    scrollbar-arrow-color
    scrollbar-base-color
    scrollbar-dark-shadow-color
    scrollbar-face-color
    scrollbar-highlight-color
    scrollbar-shadow-color
    scrollbar-track-color
    scrollbar3d-light-color
    shape-rendering
    stop-color
    stop-opacity
    stroke
    stroke-dasharray
    stroke-dashoffset
    stroke-linecap
    stroke-linejoin
    stroke-miterlimit
    stroke-opacity
    stroke-width
    style-float
    text-anchor
    text-autospace
    text-decoration-blink
    text-decoration-line-through
    text-decoration-none
    text-decoration-overline
    text-decoration-underline
    text-justify-trim
    text-kashida
    text-kashida-space
    text-line-through-color
    text-line-through-mode
    text-line-through-style
    text-line-through-width
    text-overline-color
    text-overline-mode
    text-overline-style
    text-overline-width
    text-rendering
    text-underline-color
    text-underline-mode
    text-underline-style
    text-underline-width
    touch-action
    vector-effect

NOT SURE
    -epub-caption-side       // discussion here: http://lists.w3.org/Archives/Public/www-style/2013Aug/0430.html
    -epub-hyphens            // all these properties are available in unprefixed form
    -epub-text-orientation   // in modern browsers. i have no idea if epub readers
    -epub-text-transform     // actually implement them. honest question: how many
    -epub-word-break         // people are writing CSS targeting epub readers?
    -epub-writing-mode
    -moz-text-size-adjust    // text-size-adjust only implemented in mobile safari,
    -webkit-text-size-adjust // where it's buggy. property is "at risk" in the spec
                             // and the entire spec is at risk. still, i'm taking
                             // it out of illegal and simply not highlighting it
                             // for now

Not sure if you want to include another section to this doc with elements that may have been in the HTML5 spec at one time (and possibly partially implemented in some browsers), but no longer are part of the official spec. "hgroup" is one such element. It does still exist in the WHATWG version, however.

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/hgroup

Since Installing CSS3 and disabling CSS I no longer see !important in the hints. Not a big deal unless you're working with a Wordpress theme that requires this declaration. Unfortunately I'm working with a Wordpress theme that requires this declaration in order to override the defaults.

Come on people! Delete existing CSS package and tons goes blank, where hints should happen. I am left always using multiple hint titles, last used goes to top of hint list. When is this "CSS3" plugin going to be completed? 2100? Millennium 3000?

CSS3 doesn't offer an !important completion by design. !important should be used rarely, and you should have to think about it when you use it. The extra friction of having to type all the characters in !important is intentional. CSS3 also doesn't offer deprecated and non-standard CSS as completions.

I understand there are practical concerns and legacy browsers are still around, but browsers have come a long way in just the last year. Most of the web has moved to evergreen browsers. A lot of the hacks and -vendor- prefixes of the past aren't necessary any more.