Making me chuckle at the levels of misinformation people get told.

PNC vehicle check will only have markers if required, normally naughty boy/girl markers, local box markers are recorded per force and will be associated vehicle information (reports of dangerous driving not issued with a S59) ANPR will show these markers as well as insurance / MOT status.

Only when a person's check is done will it flag SGC/FAC holder.

Back on the OP though in the late 80's I was stopped on the M25...

'Whats in the boot sonny?’

'Bren gun, L1A1, Mossberg pump, Glock and 2 Smith handguns'

'Yeah, yeah who do you think you are the bloody A-Team?'

Handed them my RFD as I opened the boot, their faces were a picture.