Go to page 39 of the
7th Issue, SAR Activity Review... It contains the descriptions of the reasons for filing (check boxes) on the legacy SAR. Tied to the old form or not, it's still very helpful in providing a cogent description of many specific types of illegal activity.
The checkboxes on the FinCEN SAR are simply a mishmash. Some terms describe the activity. Some are crimes. Some, some are just words. All of those little boxes and the "check all that apply" instruction neutered their ability to identify trends in the reporting of specific crimes.