Alumni Associations limited in ways that chapters can't?

[naraht]

I'm curious as to whether any Fraternity or Sorority out there has alumni associations which are limited to specific brothers using criteria that chapters would not be able to use to limit brotherhood.

For example, your fraternity allows all Christians to become brothers, and there is a recognized alumni association for Catholics only.

or, your fraternity is for limited to Engineers, but allows all engineers, and you have a recognized alumni association for only those with Electrical Engineering degrees.