What Do AQS, QC, and QS Stand For

What do AQS, QC, and QS stand for in the Source Template list? I can figure out the E!, EE, and CYS.

From Help
Ref – a Reference to the style guide from which the template was created. EE = Evidence Explained, QC = QuickCheck model in EE (QC-3 indicates a QuickCheck model in chapter 3), E! = Evidence!, QS = QuickSheet, CYS = Cite Your Sources.
Source templates

Thank you BobC. That’s helpful.
Polly