Joseph Wright writes:
 > Hello all,
 > 
 > I find that although there is \tlist_if_in:nnTF, there seem to be no
 > :nnT or :nnF variants.  Deliberate?

I wouldn't know, I guess when Morten  started to code the tlist module that
was overlooked. I'm all for orthogonal basics so we should add those variants
(or rather use variant generating code (which was probably not available at
that point)) 

frank