Purpose of Holes in Stove Collar

I have a question regarding the collar/flue that comes off of my stove. On the stove itself the 3 holes are one in front and one on each side. On the stove pipe the three holes are equaly distance from each other.

When attaching the stove pipe:
should I drill new holes in the pipe to align with the holes in the collar?
Should I drill holes in the collar of the stove?
Or should I just put the screws in without drilling anything?

I looked a number of stoves and some are like mine while others evenly space the holes out. I've also seen stoves with no holes. I'm not sure of the purpose of these. Any help would be appreciated. Thank you

I have never seen stove pipe with pre drilled holes; very nice. Normally you put the holes where you want them.

some of these holes were made for MPD's that for some reason are gone now or were sold as optional, your placing your mpd farther back in pipe most likely so don't worry about the holes as long as your pipe covers them, you can use the other pre drilled holes to secure the pipe to flu collar (or simply do what I and many others do... use a large stainless hose clamp at the connection to stove flu).

They are probably for sheet metal screws to hold the flue in place. If there are none---- drill them, it's the law.

The holes on the flue are threaded. The local installer said to drill out the pipe to match the holes and screw it on. I wish the pipe manufacturer gave better instructions. Oh well, almost done.

I have seen stove pipe with predrilled holes, I believe it was a T, and an elbow. I usually by my pipe from a friend that is a HVAC guy and the suppliers are considered professional, you cannot go in off the street and buy.