Originally posted by DarkSaint85
Reasoning? Not being a d!ck, but I would've thought a crossover with Aliens would not be allowed.
I think the "no crossovers" thing was really made for DC/Marvel crossovers as those would cause heated arguments on whether canon or not, due to one side not liking the outcome. But anyways, SUPERMAN/ALIENS is canon for Post-CRISIS/Pre-FLASHPOINT as it was directly referenced in a regular Superman title, including an editorial note in the panel telling the issue reference. And the sequel references the prior SUPERMAN/ALIENS, so it seems like the sequel would also be canon.