In article ,
wrote:

In the northeast there are 2 sets of "preferred routes".

thera are TEC routes, and there are preferred routes.

Which one you get will often depend on your altitude.

This is one of the more brain-dead things the FAA does. There may be good
reasons why, from an internal FAA point of view, there are two sets of
routes. From a user perspective, however, it's absurd that they're not
folded into a single table.