Sarcs,
'Officially' its only BoS that are IRM's
Originally Posted by AIP ENR 1.14
REPORTING - ALL AIRCRAFT OPERATIONS
2.1 IRM
2.1.1 IRM for all aircraft operations are:
e. breakdown of separation standards, being a failure to maintain a recognised separation standard (vertical, lateral or longitudinal) between aircraft that are being provided with an ATC separation service.
I'm not sure what the official line is on LoSA