The system transmitting the I record (primary) must set the features bits in the I record showing the features that are both present and desired. (The system programmer may have the option of not enabling a given feature on a given line.)

When an I record is received, the secondary node must look at the extended features bits and for any features that it is also willing to use and must transmit the corresponding feature bit in the J record. The secondary node should then use the features. Upon receiving the J record, the primary node should then examine the features bits and use any features that are specified. See Initial Signon Record in Formats of NJE Transfer Units for a description of the actual bit definitions.