In general, checking in commented-out code is wrong as it creates confusion amongst those who are not the original author and need to read or amend the code. In any event, the original author often ends up confused about the code after 3 months have passed.
I espouse the belief that the code belongs to the company, or team, and that it is your responsibility to make things easy for your peers. Checking in commented-out code without also adding a comment about why it is being retained is tantamount to saying:
I don't mind if you end up all
confused over why this stuff is here.
My needs are more important that yours
which is why I have done this. I do
not feel any need to justify
to you, or anyone else, why I have
done this.
For me commented-out code is normally seen as a sign of disrespect from a less that thoughtful co-worker.
