Proposed new variant subtag: pre1917

[Yury Tarasievich]

On 09/11/2010 10:38 PM, CE Whitehead wrote:
...
>> So you have Peter 1708, something 1750, and something with more disused
>> letters, in addition to modern post-1917 orthography. So you need three
>> subtags.
...
> I also agree with Doug's post that a year is not a particularly good identifier for a variant.
>
> One question:  are there are sufficient differences in all three orthographies to warrant three subtags
> (of course even a trivial difference can be catalogued with a variant subtag, if that is what you need).  If so, then one subtag, maybe [pre1917] would do.

So make the subtags referring to the number of 
letters in those alphabet variants. E.g., 
[cyr44let] or something like that.
Seems like a safe choice for the pre-1917 Cyrillic.

-Yury