- Inside–outside–beginning (tagging) : The IOB (short for inside, outside, beginning) is a common tagging format for tagging tokens.
- I- prefix before a tag indicates that the tag is inside a chunk.
- B- prefix before a tag indicates that the tag is the beginning of a chunk.
- An O tag indicates that a token belongs to no chunk (outside).
- Tagging:
- geo = Geographical Entity
- org = Organization
- per = Person
- gpe = Geopolitical Entity
- tim = Time indicator
- art = Artifact
- eve = Event
- nat = Natural Phenomenon