CLASSIFICATION CHART

Division I NAC and National Championships are always Group A4 events.
Division I-A National Championships are always at least Group A3 events.
Division II NAC and National Championships are always at least Group B3 events.
Division III NAC and National Championships are always at least Group C3 events.

Regarding ties for third place:
Third place earns the appropriate rating (i.e., a "B" at a Group A1 competition) whether there is one 3rd, two 3rds, or more (ties in a pool final). All of the third place finishers get whatever classification is appropriate, according to the strength of the competition.