Interesting. I had advisories on the ARB droplinks on my ancient Espace shed 3 years running, based on what he thought looked like adjacent discolouration from a deteriorating bush sleeve at the chassis ends. However they didn't show any other sign of failing, and the same inspector didn't list them as advisories last time around, having concluded that if 4 years hadn't made any difference they must be OK after all. I always thought the discolouration was just Copperslip residue
But the question arising is : can advisories be issued against non-MOT items then? It sounds like it.
The short answer is: YES
Long answer in "lay man's" terms:
Any part of a vehicle that is deemed to be defective in some way can be given an advisory notice
ONLY if it is in a state of deterioration that could possibly effect any other "tested" parameter item within the given twelve month period.
It's a hit and miss process that is up to the discression of the MOT examiner.
Advisories Are simply just that, A piece of advice that something has the possibility of becoming defective within a year and should really be taken care of , usually a "testable" item. But in this particular case of drop links as an example... In order to prevent further issues affecting "testable" safety items like wishbone suspension bushes.
Many owners are often under the misconception that an examiner is actually stating that the vehicle is safe for another year by passing an MOT.... They aren't, they are stating that on the day of the MOT examination, the car was or was not presented in a safe, working condition, thus a pass or fail is issued.
The time period of one year between examinations is a maximum allowed period in which the examiner has to assertain if any part is possibly going to become defective within that alloted time.
As you can imagine, this is very difficult at first without years of experience to get exactly right every time...
Thats what an advisory notice is also meant for, it's a back up for the examiner to make the owner legally aware of a possible failure within a year albeit either testable or a non-testable item if he isn't entirely 100% sure on.
After all, he can't fail an item that is within parameters of the test, That would be wrong and unfair to the owner..... But he certainly can see or feel signs of movement starting... But then again he also doesn't know what conditions and mileage the vehicle will be subjected to either as an example. So if in doubt, advise!
As far as one examiner issuing an advisory and another not, well again... Thats simply down to the difference of experience and discression of the tester
I hope this answers your questions HTH
Vehicle testing manuals and guides