The error is "missing keyword" which tells me that my syntax is bum, which makes sense since I'm having trouble figuring how to format this statement.

I get that error when I do with IF:
CASE WHEN o.mname is not null THEN o.mname || '.' ELSE IF a.a_name is null THEN '' ELSE a.a_mname || '.' END as middlename,

It works fine without the IF in the middle. I've tried a CASE there too. I suspect either will work if I knew how to format it.

What I've read of nvl() is that it replaces a value when null is encountered. That's the opposite of what I need. If there's something there, I want to add a '.', but if it's null, i want it to stay null.