First:
The more I use Ulysses, the more I like it. Thanks and keep up the good work.

Second:
About footnote tags:

I seem to have varying results when I try to use something other than {{FN}}. I can't tell if it's a Geist of some kind or my own inattentiveness, but it seems that Ulysses converts my idiosyncratic tags back to default. I tried using a single curly bracket - { } - and they mysteriously reverted to double - {{ }}.

Can I define my own footnote tag, as I can for paragraph and inline styles?

EDIT: Sorry. I think I see what was happening. I had set the document to be exported according to a template that used the 'default' tag, so there was a conflict which Ulysses resolved by using the template. Makes sense. It seems, after all, that I *can* use a single curly bracket as the footnote tag.