Guides
What is an EDI guide?
You and your trading partner must agree on the exact format for each transaction type you plan to exchange. In practice, the larger trading partner typically dictates a format that the other trading partner must follow.
These requirements are defined in what the EDI industry calls an implementation guide, also known as a companion guide, EDI reference guide, or just a guide. An implementation guide is similar to a Schema definition, with a few peculiarities specific to EDI.
You need an implementation guide for each transaction type you plan to exchange with your partners. For example, you need an implementation guide for an 834 benefit enrollment and a separate guide for an 835 Electronic Remittance Advice (ERA).