Lately I've been using VARCHAR with unique character codes for what would
otherwise be a foreign key relationship with another table with a handful of
entries, like M/F for gender, or A1-A7 for address location types.  
Elsewhere, I define constants with the appropriate humanized values.

Anyone else doing that?

Unless you're dealing with a large number of values or they need to be easily
updateable without an application restart, it's probably sensible.  From a
normalization perspective, it just feels deeply wrong, though.

I'll entertain suggestions for the normalization approach if there's something
I'm missing, though.