From Open Risk Manual

This category defines concepts relating to contracts, for use in other FIBO category elements. These include written contracts which are the concrete evidence of agreements between parties, along with verbal contracts.

Contracts are further broken down into bilateral and transferable contracts, the latter being the basis for most financial instruments.

Properties of contracts are also defined, in particular contractual terms and contract parties. These concepts all form the basis of concepts in the financial services industry, for example interest payment terms are a kind of contract terms set, and security holders are a kind of contract counterparty.