These will only be consumed by GetAggregateStatsByActivity
Only applicable while generating leaderboards.
This is purely to serve as the dividing line between filterable and un- filterable groups. Below this number is a group you can pass as a filter. Above it are groups used in very specific circumstances and not relevant for filtering.
These are only consumed and returned by GetUniqueWeaponHistory
If the enum value is > 100, it is a "special" group that cannot be queried for directly (special cases apply to when they are returned, and are not relevant in general cases)