The document discusses three categories of "terrorist related events" that can affect humanitarian agencies:
1. Attacks against aid agencies by armed opposition groups, which includes 238 events.
2. Incidents where aid workers are caught in crossfire during military action between government and opposition groups, with 88 events.
3. Incidents where governments hinder aid delivery through administrative measures or law enforcement intervention, with 71 events.
The document analyzes differences between these categories, such as weapons used and impact on aid operations, to understand how terrorism may uniquely affect humanitarian work.