Well Andy:

I think that the expression TBD has literally become word via the rules of common usage. I hear people say TBD all the time. Now don't get me wrong. It is kinda wierd that when people "say" this word it comes out TBD as if they were spelling it. But a "word" none the less.

The dictionary at the online site that I use does not specifically state that the abbreviation formed in the creation of significant letters from a multi-word phrase has to be a word that is "pronouncable" according to some type of language rules.

For example, here in the USA we all pay income taxes to a federal government agency known as the Internal Revenue Service. We all know that the acronym IRS refers to this agency, whom we all love sooo much. Yet when the common usage of the word IRS comes into a conversation the "pronounciation" for it comes out in a spelled manner. I for one would never consider IRS to be an abbreviation.

It is for this reason that I'll stick with my declaration that TBD is an acronym and not an appreviation. If in the sometimes instances when one sees it written as "t.b.d." then I'll go along with it being a simple abbreviation.

Michael Karas