EIR
Employer information requirements: what the client needs in terms of information.
The EIR, employer information requirements, describe which information the client needs from a project. They come from the client and stand at the beginning, before the tender.
A good EIR names use cases, the level of information need derived from them per component group, formats, naming conventions and the split of which data the client supplies.
Without an EIR the provider decides what gets delivered. Bids become incomparable, and in operation exactly the data that matters is missing.
The counterpart on the provider side is the BEP.