>In my pull request, I had noted that a given test suite and the associated code weren’t actually used and working and so I was commenting them out. At the time, he told me to delete the lines instead of commenting them out; citing that “dead code” (e.g., unused, unexercised or otherwise unneeded code) served as a greater liability than source of future implementation and re-use.<p>I <i>generally</i> agree with this sentiment ... but while a <i>likely</i> good rule-of-thumb, you also have to know when it's <i>NOT</i> good to apply<p>If you have version control, it's almost always correct - delete away, and revert if you need to<p>But when you <i>don't</i> ... commenting-out (and dating when it was commented) ends up serving <i>as</i> a [very] poor man's version control<p>I end up having to do this (or make copies and only work on the copy) with the product I use most for work because it has <i>NO</i> concept of version control anywhere ... and the add-ons that attempt it do it very poorly