[css3-lists] Allow alphabetic numbering to be treated as symbolic

I work for a government agency, where alphabetic numbering beyond item
26 is formatted on paper reports as AA, BB, CC (as opposed to AA, AB,
AC). The only way that I can accomplish this in HTML/CSS is overriding
the sequence number of each item after the 26th item. This is not only
tedious for long lists but does damage to the semantics of the items.

http://www.w3.org/TR/css3-lists/#numeric indicates an alphabetic
numbering scheme of ...Z, AA, AB, AC... while what I am looking for fits
more under http://www.w3.org/TR/css3-lists/#symbolic. However,
http://www.w3.org/TR/css3-lists/#symbolic is currently limited to
asterisks and footnotes.

I respectfully propose that any alphabetic list be renderable as if it
were symbolic by adding -symbolic as a suffix to the system name, e.g.,
upper-alpha-symbolic would render AA for item 27, BB for item 28 and CC
for item 29, etc.

I see this discussed in a 1995 archival post
http://lists.w3.org/Archives/Public/www-style/1995Oct/0004.html but
nothing after this. I'm surprised this hasn't come up more often as I
would think AA, BB, CC numbering is not that unusual. I note that
choosing number style A, B, C... in Microsoft Word produces AA, BB, CC
for the 27th through 29th items, so this would be a potential issue for
any document converted to HTML from Word. While I am not suggesting CSS
should conform to Word, neither should CSS be hostile to its
conventions.

Hope this helps,
Charles Belov
SFMTA Webmaster