Sentence:  Follow-on training would take place after completion of the basic apprentice or craftsman courses. Three-level students would attend ATHRS training, and select <WSD>7-level</WSD> students (approximately 49 per year) would attend AFBDS training. 
Meaning of the word marked with <WSD> tags:  A person who has qualified for "Craftsman" level of skill in the United States Air Force, with more training than "Journeyman" (five-level), but less than a "Superintendent" (nine-level)