Over the years an old code base accumulates a lot of  junk left over by programmers. Some of this is what I call vacation signs. This is a small explicit statement left in the code in the form of a comment (or a bug) stating that the developer was there. For instance:

// mjm - 06.12.00 - begin

...

// mjm - end

So now, not only do I know where his changes started, thankfully he informed the entire world where his changes ended. This is equivalent to taking a vacation to Italy and pounding a small sign in the ground when you arrived in a town stating “I <insert name here> arrived in Milan on Feb 1 2004″. And imagine when you left, you then pounded another small sign into the ground (perhaps at the other end of town?) stating your name and the date that you left. This is cute for the pictures send to your mom, but sooner or later the mayor of Milan will start to get offended at stupid tourists who do this, and will send the constables to arrest the idiot foreigner who is littering his town. This if course is utter stupidty. And in the case of these vacation signs left in our code above, they are an utter nuisance. Especially when there are thousands of these little signs.