OBO Format (OBOF)

What it is This is the working-draft specification for OBO Flat File Format 1.4, providing a BNF grammar and a mapping to OWL 2 DL. It defines how physical OBO files parse into abstract documents, imposes structural constraints, and gives their semantics through OWL translation rules.

Key concepts An OBO document has one header frame followed by zero or more term, typedef, or instance frames made of tag/value clauses. The specification covers identifiers and frame merging, tag cardinalities, header macros, OWL mappings, an owl-axioms escape hatch, the restrictive OBO Basic sublanguage, and informative OWL macros.

How you’d use it Use it to implement or validate OBO parsers and serializers, translate OBO constructs into OWL 2 DL, or determine whether a document satisfies OBO Basic assumptions such as being a DAG, fully asserted, fully labeled, and free of imports and dangling clauses.

LLM angle none stated

Pitfalls & lessons The document labels itself a working draft and says some parts may be unstable. Translation into a sublanguage is generally lossy; arbitrary OWL axioms can round-trip through owl-axioms but remain opaque to many OBO applications; and the specification explicitly says OBOF is not a good choice for knowledge bases that use individuals.

Verdict The authoritative source in this fetch for OBOF 1.4 syntax and OWL semantics, but its draft status and legacy-compatibility constraints matter when implementing against it.

Sources consulted

• http://purl.obolibrary.org/obo/oboformat/spec.html