There is several types of oceanic procedures. NAT tracks are the most common ones. NAT track means North Atlantic Tracks. They are over the north atlantic ocean. 2 types of it - westbound [ Europe - USA and Canada ] and eastbound [ USA and Canada - Europe]. If you fly over an ocean before entering the NAT track you'll need to advice ATC about the routing you're going to follow if there is oceanic clearance ATC there. The way you need to speek the clearance is splinted. I'll give you example:
1.Let's say you are doing flight from KJFK to EDDF. You're going to follow NAT track that is containing this waypoints: NICSO 4850N 4940N 5030N 5120N DINIM ELSOX . Here's how you have to read it: Via NICSO 48 North 50 West, 49 North 40 West, 50 North 30 West, 51 North 20 West, Direct DINIM, Direct ELSOX.
NAT Tracks are changing every day. Usually I use the Skyvector.com website. I know that in 19:00 or 20:00 Zulu is goign to change the route. Route is based on wind data, it gives you the best oceanic route to pass faster the ocean. You will have to do a position report on the NAT track if there is ATC to control from the shore. The prev. guy already spone about it.
There is also a PACOTS tracks. They are for the Pacific Ocean Traffic system. There is similiar procedures, but the tracks are a bit confusing mostly.
The most confusing from the all tracks are the Domestic and the Middle East Indian Ocean Tracks. They are created for routes from the middle East to Australia east and west coast. Also for connection routes in Australia from the west to east coast and to Mallaasisa under the Asia tracks. Those groups are different, there handling system includes the airports and approaches to specific towns, like Sydney, Melbourne etc. Tbh I still do not understand them. I hope my comment helped you.