How do I find CSS 2.1 property replacements that are missing in CSS 3?

Question

W3C maintains an excellent list of all CSS properties, both current and proposed . Of the 115 properties marked as CSS 2.1, sixteen of them are not part of any CSS module (for level 3 and above). It:

azimuth, height, line height, break-in pages after, break-in pages before, break-in pages inside, pitch, pitch, play, wealth, talk-heading, talk-figure, talk-punctuation, speech speed, stress, Volume

Now I know the W3C instruction, from CSS Snapshot 2015 , which states: “Each module adds functions and / or replaces a part of the CSS2.1 specification. The CSS working group intends that the new CSS modules will not contradict the CSS2.1 specification: only they will add functionality and clarify the definitions. " However, there seems to be no update path or list of deprecated properties.

I'm sure modern browsers, for reasons of backward compatibility, will prefer the well-defined and stable properties of CSS 2.1. But someone (perhaps the people responsible for a particular module) decided that the properties of CSS 2.1 were clumsy, hacked or otherwise did not fit into the clean world of CSS 3 modules.

For example, I searched the CSS Speech Module to see if speak-numeral is mentioned (one of the missing 16). This is not the case, but I found speak-as , which seems to have the same functionality.

So, programming and programming issues here:

• Why are these 16 properties not deprecated?
• Is there a guide to upgrade to CSS3 somewhere?
• What is the strategy for new web applications? Do we continue to use these old properties until the module makes the recommendation status and / or receives improved browser support? Is it a good idea to use both properties (old and new) in a stylesheet?

Answer 1

Take one example, I suspect that the most commonly used of these is line-height .

CSS Layer 3 Built-in Layout Module, Section 2. Line height and baseline alignment read

This section is overwritten. See Section 10.8 of [CSS2] for a normative definition of CSS or a 2002 working draft for beautiful images. (But ignore the old text, half erroneous. Not indicating which half to be determined.) The CSS2 specification should be used as a guideline for implementation.

Thus, it is not out of date, it is just that the description from level 2.2 is executed until the definition of level 3 is recorded. Level 3 is huge, and the work should be a priority. The line height obviously works well enough to keep this priority low. Sure, it will be considered in the end.

Others are probably similar. Their level 2 definitions have not yet been replaced.