In The Godfather Part II, Sonny introduces Michael to Carlo. He tells Carlo they call Mike "Giogali".
Who is "Giogali"?
The actual quote is:
We call him Joe College.
This is because Michael is the more educated brother and attended Dartmouth College before enlisting in the Marines. It's something of a put-down by Sonny as though Michael is different from the rest of the family.
An earlier version of the script (which had to be revised when Brando wasn't available) has a slightly different wording but the scene is essentially the same:
SONNY Hey, who knows my buddy Carlo Rizzi. Here... my brother Fredo, here's my Mom. Mom, whatcha got cooking? And Carlo, this is my kid sister Connie. Here, pull up a chair, Carol is sitting next to Connie. Oh, the droopy kid over there is Mike. **The college boy.**