Question

Eib field that indicates which attention key was used for the last receive command

Answer 1

EIBAID is the EIB field which indicates the attention key which was used in the last receive command.

It is as long as 1 byte and used to hold the original attention identifier value until the 3270 input stream.

It is one of the attention identifier keys used by the CICS to control the functions after receiving inputs from the user.