"only happens" is a lot more often that you think. In my experience, "only" is q...

"only happens" is a lot more often that you think. In my experience, "only" is quite frequent.

A randomly picked case in point:

Debian has had a local manual page for the original software's undocumented (in the old Sourceforge version) iptunnel(8) command for 7 years:

Independently, the original came up with its own, quite different, manual page 3 years later:

Then Debian imported that!

This sort of thing isn't a rare occurrence.