On the "We Speak English on This Blog" thread, quite a few comments said more or less this:

This is silly.

Use the correct title - it's a matter of courtesy, not clarification. We're not talking about a "select few" here, we're talking about millions of active and former military, many of whom are risking or have risked their lives so you can sit around and whine about differences between the services.

Generally, no one is writing about service members without looking at something else written about them - so there is really no excuse for getting it wrong. There is no need for civvies to actually memorize this stuff.

The trouble is that this argument assumes that what is "correct" in the source language or jargon is also the only correct approach in plain English. My point is that it is no less correct to translate from the source language or jargon to the plain English idiom.

Thus, the correct title for a Russian colonel is "polkovnik" -- correct, that is, in Russian. In common English, "colonel" is a correct translation, and there's nothing discourteous about that.

Likewise, the correct abbreviation in military jargon for a naval captain is apparently "CAPT" -- a departure from normal English abbreviation conventions, but military jargon has its own conventions, to which it is entitled just as normal English is entitled to its own. Yet when one is using normal English rather than military jargon, "Capt." is a perfectly correct normal abbreviation, and there's nothing discourteous about that.