Unfamiliar ATC terminology
During one of my earlier PPL lessons, we received traffic information from ATC about someone on short final, whilst we were joining on left base. My instructor at the time told me to reply 'ROOKIE' in response to this.
Having since done the CAP413 RT course, there was no mention of 'ROOKIE' in standard RT phraseology. Can anyone tell me what this means?
I would ask the instructor but I have since moved home / flying school.
Thanks in advance.