Crafters with Master Rank

[Jane]

Quick question.  What level of Triad rank are crafters who are masters?  There are references to them as L3 and L4, but the wording is slightly different so I'm wondering if I'm missing some subtlety.  (I get the Hallmasters = L1 and Hallseconds = L2 stuff.)

TIA

[Bree]

It is a little tricky, and needs to be fixed. ;)

Hallmster = L1
Hallsecond = L2
Weyrhealer/Weyrharper/Master of Apprentices - L3
Master Crafter with no other special rank - L4