Since I’ve been riding in London I’ve seen quite a few bikes with a little black rat sticker on the number plate…I’ve been told that this means that the rider is an off-duty copper…is this true? If not I’ll stop riding like i’m on an IAM course each time I see one 
Black rat=Traffic plod.
Those little stickers can be picked up on ebay, and normal members of the public sometimes use them thinking it’ll help them avoid a tug 
They even do these now http://cgi.ebay.co.uk/Police-Black-Rat-Number-Plate_W0QQitemZ220051466878QQihZ012QQcategoryZ52638QQrdZ1QQcmdZViewItem
Just ride your normal ride. Ignore them.
The Black rat is the adopted symbol for the Traffic department. Where it came from I’ll leave that to Pork or Darrylj to answer as I haven’t a clue … each specialist unit does have their own symbol hence my user name and the picture here.
A few of the Traffic lads wear the ‘rat sticker’ on their vehicles and so do many many of their families and friends and also other members of the public - I think I’ve even seen them on ebay !
The rat you see is this one as displayed on Darrlj’s member page - http://londonbikers.com/forums/userinfo.aspx?id=106
Before you ask, the days of a sticker doing you a favour have gone ! 
I think it comes from the first traffic (maybe motorcycle?) poilce units used by the Met they were nicknamed The Commissioner’s Balck Rats…Well that was according to my old man who did 30 years in the job.
You can also call them Cheese cutters but that doesn’t go down well at all…
I wouldn’t worry about tempering the way you ride most off duty coppers I know are absolute nutters on a bike, while maintaining the highest safety standards of course.
a work colleague who is a retired traffic inspector, suffolk constabulary, has told me they were called black rats because black rats will eat their own if hungry enough, and traffic police issue tickets to other police officers, on and off duty.
is it true???
who knows, but it made me chuckle, as a long standing friend who is a sergeant in the met, has 3 points after being tugged at 85 in a 70, by a met traffic police, while he was off duty. he was in half blues (police trousers and shirt under a civvy jumper) and still got done.
If you can keep up with them (most will speed but not do silly things like go on the wrong side of a traffic island) then it is a fun ride. Don’t sit on their ar$e and they will be your radar for the police, cameras, etc
Police are not above the law.
Weren’t black rats responsible for carrying the plague?
And even worse they carry radar guns now !
No one said they are mate, I fully agree.
Pm me mate, though I don’t think I’ll be much help really, I went through all the assessment stuff 16 years ago and things are very different now.
So Trojan, you’re name isn’t taken from a popular brand of American johnnies then?
Black Rat.
The Black Rat symbol is just that.
A symbol of the Police MOTORCYCLIST.
traffic departments on the whole started to adopt the symbol but it was the bikers who owned it…traffic car drivers are not Black Rats.
the Police motorcyclist is the original Black Rat and we’re proud of it!
i have a small one on the rear of my lid, you can’t see it from any distance , it’s just my belonging to the ‘club’…i have none on my bike as i don’t need to advertsise my proffession…
The origins are varied but the two main ones are the fact we eat our ‘own’ (prosecute police officers ) and in the early days we wore all black leathers and on the rear of our bikes we had waterproofs etc rolled up which had a release lead which would flap around on the move giving the impression of a rats tail…
The rats sticker is available to buy, but it will certainly not become a ‘get out of jail’ card for anyone, in fact it may have the opposite effect, as an officer might be intrigued as to why your wearing it…
So, PS, do share. Have YOU ever had a speeding ticket, or any other motoring contravention? Would be interesting to know though of course we’ll understand if you decline to answer (nod, nod, wink, wink) 
Right…
last year at Box Hill.
£30 fixed penalty notice for small plate.
year before at Box hill
VDRS (def rectification) for race can (viper on a 929 blade)
apart from that, nothing.
What a lovely chap - even admits to being falible (or to getting caught, at least!)
Why, thank you