I know that Chi Omega will "recycle" chapter denotations, because there used to be Chi Omega - Phi chapter at Hellmuth College (now closed) in Canada. Then Phi chapter closed.
Then it was Chi Omega - Phi chapter at USC.
That chapter is now closed.
In checking in at
www.chimomega.com, there doesn't apprear to be a Chi Omega - Phi chapter in existence at present.