In my experience you absolutely SHOULD document every request and removal in e.g. an issue tracker. It's very valuable information. And commented out code gets

In my experience you absolutely SHOULD document every request and removal in e.g. an issue tracker. It's very valuable information. And commented out code gets stale so quickly. Much better to check out an old version where it still worked than uncommenting a bunch of lines that now have compile errors and have become incomprehensible. Happens so easily, e.g. after some variable renames.