Who you're supposed to be able to appoint to dukeship

[Kain]

Who are you really supposed to be able to appoint to dukeship?

The options my ruler gets are three margraves from other duchies, a rural lord from another duchy, two woodland lords from other duchies, a mountainous lord from another duchy and a very new noble who hasn't taken an estate yet.

So my question is still, what happens if she appoints a margrave or a lord from another duchy? Will she be able to appoint knights if they give up their estates first?

[Telrunya]

I think, not sure, that the region in question will/is supposed to join the Duchy when the Lord of another Duchy is appointed Duke. However there seems to be a small bug at least with Elections in that the region won't change allegiances even if a Duke of another Duchy is elected to that (So you end up with a Duke having a region in another Duchy, which doesn't seem intended)

Knights cannot be appointed Duke as that will constitute a break in Hierarchy (He'll be the Duke of the Lord he owes allegiance to as Knight). If he vacates his Estate, he'll be able to be appointed Duke since there won't be a mess-up in the Hierarchy any more.

[egamma]

The only persons you should be able to appoint are lords from the duchy the dukeship is for, and nobles without estates.