# What does “representation spanned by the antisymmetrized product of a degenerate representation” mean in direct product tables

In some tables for direct products (e.g. the one for $$C_2$$ here), some of the components for direct products of irreps (seemingly only for degenerate irreps) are "the representation spanned by the antisymmetrized product of a degenerate representation with itself".

What exactly does this mean?

• Minor comment to the post (v1): Please consider to mention explicitly author, title, etc. of link, so it is possible to reconstruct link in case of link rot. – Qmechanic Jul 2 at 6:38