HP auroraTempo User Manual page 219

Introduction to Frame Relay
However, in order to narrow the standards and prevent any
scope for incompatible equipment, the Frame Relay Forum
published its own 'implementation agreement' e.g. FRF.1. It
is this, rather than the international standards, that has been
the main design document for many manufacturers of Frame
Relay equipment.
The key Frame Relay standards are shown in the following
tables:
Issue 1a - 10/99 8-5