sometimes I stumble across things I want to remember or write down and sometimes I actually do it. This is like my own directory of man pages with examples to get back to in the future if I need to. Most of the time I just forget this stuff exists or I don't keep it up to date. But hey.
When I created something on my own it's my own stuff without a source, otherwise I'll usually put a source link in the file as well. The only source probably is stackoverflow anyways!