"Formally, this renders this particular individual uncountable on anything but a personal list."

Forgive my asking, but what other kind of lists are there? Do birders compete professionally with
some type of "approved" list? Why does anyone care? I'm not being sarcastic, I truly don't know.
Til this hummer hoo-ha I had no idea there were official lists approved by official committees.
The idea seems silly to me, so... I'm asking.