What have you done with UDAs?

[Tofu Ninja via Digitalmars-d]

On Monday, 22 June 2015 at 19:09:40 UTC, weaselcat wrote:
> I never seem to use them for anything, has anyone else done 
> anything interesting with them?

I am currently writing a ui system that defines the majority of 
the layout in a dsl. The ui element types are defined in D code 
and I use uda's to mark which fields can be accesses by the dsl.