I have observed that some CSS properties, like font-family
declared with quotation marks, perhaps are case-sensitive, but all other are not... But how web-browsers and "HTML renderers" MUST interpret? Is the same in any CSS context (XML, SVG, etc.) and all other applications? What the standards say about?
Example: Adobe InDesign exported both, font-family:'Optima Bold'
and font-family:'optima bold'
. Can I "normalize to lower case" (ex. to merge similar classes)?
NOTES
References are incomplete and in conflict:
sitepoint.com/font-family say "Note that font family names may be case sensitive on some operating systems"... It is valid for XHTML, it is updated with HTML5?
font-family
is really the unique case-sensitive value?Is it necessary to use lowercase for every Element and attribute , properties in css and xhtml ? say indirectly "... use lowercase for every properties...", and answers not negate it.
Comparing with this question/answers, the point here, perhaps, can be translated to some (personal) objective considerations:
There are a (objective!) normative (W3C spec of CSS2, CSS3, XHTML1, or HTML5) source for this answer?
"Standard
font-family
unique names" can not be case-sensitive (otherwise cease to be standard)... So, the only justifiable (by sensible arguments) properties to be case-sensitive are:2.1.
X
values aturl(X)
, seebackground
, etc. properties;2.2.
content
values, example;2.3. ... more ?? ...