Num tags in Arabic

[jcowey]

When Arabic texts use Greek letters, perhaps put xml:lang="grc" on the num tag.

<num xml:lang="grc" value="24">κδ</num>

[hcayless]

I worry a little about this because it's not really a language thing. Would @type be better? Like:

<num type="Greek" value="24">κδ</num>

be better? I'd be interested to know if other number types show up too...