Alaska transoceanic flight planning

I'm trying to plan a flight from Anchorage to Hong Kong and have been doing some flight planning research.  I've been studying some routes on flightaware.com and see that many routes include NOPAC routes and OTRs in the flight plan. Is there a set of NOTAMs or ICAO rules that govern transoceanic flight planning to include certain tracks or other routing requirements when flying transoceanic routes to/from Alaska?  I'm a little new to this so some of my terminology might be flawed.

Todd