Not totally sure, Dr B would know. But from my understanding level 3 is highest accreditation you can get. And each area has a level, ie. Motor, tranny, etc...
My tech was level 3 across the board.
not sure about US (should be the same) but Canadian training is as follows:
other than core area, there are 7 skill areas (engine repair and performance, automatic transmission, driveline, chassis, electrical and body systems, A/C and heating & diesel systems). each skill area has 3 skill levels (1,2 & 3).
there are 7 curriculums (core, Fiat, maintenance, ProMaster, tech assessments, Viper & Alfa).
other than monthly online training and mandatory courses, certification levels are for core curriculum and are as follows:
certified - level 2 in a specific skill area.
specialist - level 3 in a specific skill area.
chassis master - level 3 in skill areas (driveline, chassis, electrical and body systems).
electrical master - level 3 in skill areas (electrical and body systems, A/C and heating).
powertrain master - level 3 in skill areas (engine repair and performance, automatic transmission, electrical and body systems).