Coder 1: Hey there! Noticed you commented out some code with your recent checkin.
Coder 2: Yes, the code was ancient and not even being used anymore. I whacked it! (karate chop motion)
Coder 1: Well, you commented it out and then added your own comment about why you commented it out.
Coder 2: Yes…?
Coder 1: …
Coder 2: What?
Coder 1: Why didn’t you just delete the old code and be done?
Coder 2: Then the future maintainers of it wouldn’t realize what I had done.
Coder 1: But we’re using source control management… history is preserved for you!
Coder 2: I know, but how would they really know? You know?
Coder 1: … (karate chop motion)