yes as in Scotland there is only two processes , Cautioning before questioning and charge , the rest is either inadmissible information or not under police service of Scotlands ability unless you are being formely charged by a rank above inspector , it is a strange process and something I have heavily read into over the years.
I am always surprised on how little powers that Scottish police officers actually have, like only having the powers of arrest after authority has been given etc, its all in the wording. PSoS constables have less powers against civilians than English police officers, one of the strangest thing though is in Scotland a police officer on a night out does not have to make you aware that he/she is an off duty officer when they enter say a nightclub but in England they are supposed to, not that they always do though.
Slightly rusty but:
In relation to common law cautions, as you said on a previous post - it’s nothing to do with anything that ‘goes on your record’ (in Scotland).
You will be cautioned (common law caution) prior to detentions for searches (like drugs searches) as well as pre arrest (no detentions for investigating crime now, only for searches), pre interview, pre charge.
These seem to get confused with England as what they, maybe do, or historically used the term ‘police caution’ for A police slap on the wrist which used to be classed as a ‘warning’ or ‘official warning’ (or some such thing) in Scotland but I think these are no more.
There are the likes of ‘Involuntary Exclamations’ which can be admissible (usually in serious crimes) when made by a witness/suspect/accused without the ‘common law caution’ being administered.
There are common law powers of arrest, statutory powers of arrest - all criminal law is common law or statutory.
I don’t know what you mean ‘charged by a rank above inspector’ as anyone Constable rank and above can charge you for any crime in Scotland. I think you may be getting confused with extensions to the arrest procedure. Really your not ‘charged’ until the COPFS says you are either as they may put a pen through it if they deem the evidence insufficient.
Powers of arrest do not need to have ‘authority’, they need to be either common law or statutory law as already mentioned which gives the power of arrest. There are few crimes without a power of arrest in Scotland but vandalism would be an example.
In relation to ‘less powers’ than in England that is pretty much all to do with powers of entry without warrant etc, which in fact can be done but relevant warrants have to be craved retrospectively prior to certain courses of action being carried out.
Back to the OP, phone a solicitor (the one mentioned several times on the thread is who I would contact) prior to Plod turning up and they will advise you what to do/say.