Historically, or at least say 10-20 years or more ago, VIP was only attached to those years in which proofs were made in limited numbers (a handful of examples), i.e. the years in which sets were not made for the masses. The years in which it applied started from 1926 onwards when a few proofs were struck of all current denominations and continued up to the early 1960s. Notwithstanding the debate about the first year which some contend are not (though I'm happy that my 1926 halfpenny is one), there are coins extant with proof quality finish for all years in between, though not necessarily all denominations for every year due to gaps in the dates of currency issues. It should be noted that not all proof coins of these rare issues exhibit frosted devices.
During the past 10 years, the phrase 'VIP' has been misappropriated in my opinion to include superior strikes with a cameo effect with a resultant explosion in the number of 'known' examples. There has been an occasional example of a set in contemporary boxes that were different to those issued for the masses, which if it could be proved were genuinely issued to 'VIP' recipients by the mint, could therefore be justifiably be classified as such. As VIP means very important person, it should include the likes of the Chancellor or the Queen, not Mrs Smith of 16 Acacia Avenue, Bognor Regis.
The whole thing is a case of semantics in my opinion, and arguably a triumph of marketing over reality.