Is There a "Guy Code" in Male Restrooms?

As a female, I have never heard of this. As many guys know, women tend to go to the restroom in groups so we can talk and have "girl time" but, in my psychology class, I have learned about this apparent "guy code" unbeknownst to me that apparently happens in male restrooms: No talking. No eye contact. Don't take the middle one. Guys, can you verify this? Is there more to this "code"? Ladies, have you heard of this before?
Is There a "Guy Code" in Male Restrooms?
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