[Persephone]

Huh? What func_wall? I was often making a map for Opposing Force CTF with Valve Hammer Editor, and I never used it. I mean, what usefulness of it? All you have to do is placing an entity called "item_ctfbase" and it has default models called "civ_stand.mdl" (for Black Mesa team) or you can rename it to "mil_stand.mdl" (for Opposing Force team). Don't forget to place entity called "item_ctfflag" inside the base for each team. So you don't need func_wall at all.