At least in the UK, such a term would have to be brought to your attention before the sale, very clearly, for it to be part of the contract. Writing that in the manual would have no effect.
Interestingly, in the UK paperback books have a little contract in the front saying you can't rebind them into hardbacks, while in the US such a contract is forbidden by the right of first sale. The moral is that these things are less obvious than one would think.
The UK certainly has some weird laws, but that sounds...of dubious validity. Like roughly the equivalent of "not for individual resale"; a contractual matter between the supplier and the merchant, not something that could even theoretically be enforced on any buyer.
I doubt strongly that this would have any effect either, for the same reason. My legal knowledge is a little old fashioned and sporadic, but the classic authority on this used to be 'Olley v Marlborough Court Hotel'. Worth a read, if only for the way Denning used to write his judgements.