Documentation: Man 1 3 and 9

I was wondering if there is a standard for when Man 1, Man 3 and Man 9 folders are used for saving documentation?

I think I have it figured out, but I think I found an anomaly and before I change something (being a noob) I thought I'd ask as the only daft question is one that is not asked.

Man 1 = userspace components
github.com/robertspark/linuxcnc/tree/master/docs/man/man1

Man 3 = API calls
github.com/robertspark/linuxcnc/tree/master/docs/man/man3

Man 9 = realtime components
github.com/robertspark/linuxcnc/tree/master/docs/man/man9

anomaly (sure there may be others):
hal_parport is a realtime component (acording to the man file) + a driver?? and is listed in Man 1 (under userspace components).
github.com/robertspark/linuxcnc/blob/mas...n/man1/hal_parport.1

should it be deleted from MAN1 and added to MAN3?
{will this create a problem if I raised pull requests as such}

here to hopefully help, not hinder and treat on toes or break anything.

Note: sorry just noticed that the links are to my fork of linuxcnc git, same applies with the master, can't be bothered to change the links, I'm sure you get the idea). I've only changed 1 file in my fork (components.txt)