I read a book over a decade ago and want to read it again but I don't remember the title or the author.
What I remember about it:
A woman crash lands on a foreign planet, finds her way to a place where they train mages. She calls magic 'ler'. Only men are mages on this world. They train her anyway and then travels with her teacher and another student to take a test of some kind to determine her level of power. These levels of power are denoted by unremovable metal rings around the mages neck. The more rings the greater the power.