Proprietary extensions to CSS

Usually implementers are advised to use a hyphen-identifier-hyphen prefix for proprietary selectors, properties, values, units etc. There are, however, some features that the W3C doesn’t want to figure out in as much detail as would be necessary for a full-fledged specification or that are useful only to a limited number of user agents, but that have a rather intuitive syntax possibly of interest to more than one vendor. 

Would it make sense then to have a module “CSS Unsupported Extensions” (or the like) that would merely register the tokens so they can be used without prefixes with a guarantee that the CSS WG will never use these in a different manner?

I’m thinking of several things here, e.g. custom length units

  1emu = 1pt/12700 (Office Open XML)
  1um = 0.001mm
  1q  = 0.25mm
  1pp = 10541mm/30000 = 0.3514mm
  1dd = 0.375mm
  1fp = 0.4mm
  1cc = 4.5mm
  1dm = 10cm
  1m  = 100cm
  1ft = 12in
  1yd = 36in

custom color designations

  pms(<number>), pms-<number>
  ral(<number>), ral-<number>
  tsl(<tint>, <saturation>, <luminance>)
  ryb(<percentage>, <percentage>, <percentage>)
  hks(<spot>, <tone>)


This could also be the place to record once defined properties and values that have been dropped from CR+ specifications.

Received on Monday, 12 September 2011 20:11:56 UTC