The set of talents, skills, capabilities, and areas of expertise possessed by someone, and generally referred to in the context of being able to be compensated for same... although not always.
Harry: Bob, I can't believe I got passed up for a promotion this performance round!
Bob: That's too bad. Why do you think that happened?
Harry: They said something about, folding paper airplanes, spell checking MS Word documents, commenting on the quality of each mornings coffee batch, and talking about sports all day not being a promotable skill set... but I wasn't listening at that point anyway because I was already so mad they weren't going to promote me!