Wolfgang:

The key words in the quote you gave are "as far as this database is concerned", which I think grows out of the operating convenience of the database designer(s).

As I understand it, there are three classes of what I'll call short forms:

Abbreviationsare short forms of words or phrases, normally in lower case letters (except sometimes an initial capital), followed by a period. Thus etc. and Mr. and so forth.

INITIALISMA group of letters reflecting a phrase, formed from the initial letters of the phrase, which group is NOT pronounced as a word. It is written in all caps, and is not followed with a period. Like IRS, USA, and here at Mudcat, DT.

. ACRONYMA group of letters formed like an acronym, but pronounced as a word, such as NASA, for instance.

Dave Oesterreich