Kristina Floyd wrote: > I am aware that the W3C states you shouldn't start identifiers with a digit > or a hyphen, I am just curious to know why? > > Can you also explain to me the meaning of the attribute value 'auto', what > are its implications? > > Is there any way to completely cancel all previous rules for a particular > tag? >
Identifiers (I'm assuming you mean the values of id attributes here) need to follow the rules for the Name production in XML, otherwise XHTML wouldn't be possible. As to why XML specifies those restrictions, I don't know, and a few minutes looking through the XML spec hasn't made things any clearer; have a look at <http://www.w3.org/TR/2004/REC-xml-20040204/#NT-Name> and you might get an idea. There's a good chance this is just down to maintaining compatibility with SGML. The CSS value "auto" means lots of different things depending on what it's applied to: as cj has already mentioned it can be used to specify an automatically-sized margin; if used with overflow, it means "honour the dimensions of the container, supplying scrollbars if and only if the content is too large to be contained within those dimensions"; and in other places it means something else again. In other words, there is no single answer; a search of <http://www.w3.org/TR/2004/CR-CSS21-20040225/propidx.html> shows 15 different cases in which "auto" can be used. Clearly it's going to have a very different effect on "cursor" compared to "top". Your best bet is to look up the definition of each of those properties and see what it means in that context. For your final question, cj has already answered it, so I won't bother :-) HTH, Nick. -- Nick Fitzsimons http://www.nickfitz.co.uk/ ______________________________________________________________________ css-discuss [EMAIL PROTECTED] http://www.css-discuss.org/mailman/listinfo/css-d IE7b2 testing hub -- http://css-discuss.incutio.com/?page=IE7 List wiki/FAQ -- http://css-discuss.incutio.com/ Supported by evolt.org -- http://www.evolt.org/help_support_evolt/
