Ah ha! My objective is to have a list of abbreviations that is intuitive, consistent, and sufficiently so that it will actually be used — such that it will become the de facto standard.
I've mulled this one several times over the years, being as pedantic as most of us here, and in pursuit of the perfect formula..
..trouble is, just about every system I can conceive gets confounded along the way!
If you use single letters for the big names, two for the 'second division' and three for the rest; you get the problem Derek identifies, of the big name line-up changing over time, and more frequent changes in the second division.
In theory you have enough permutations of two letters to go round, but in practice, this would lead to many abbreviations being wholly unrecognisable.
Then you could opt for the airport coding system - three letters that are usually an identifiable abbreviation. However, without the authority to dictate; such an abbreviation needs to be constructed according to a standard formula; and just about every formula I can come up with (that is not impossibly complex..) -gets scuppered when applied to Noval, Noval Silval & Noval Nacional, which are sometimes all produced in the same vintage.
The only real solution is to have a system that is annexed to the document concerned, and which, in our increasingly paperless age, will expand to reveal the full text when one highlights or hovers over the relevant abbreviation. Once such a system has been created by one person, others would be easily tempted to copy and paste, rather than create their own.
I may be drunk, Miss, but in the morning I shall be sober and you will still be ugly - W.S. Churchill