Translation:Don't bring me an Earth citizen! Bring me a Klingon warrior!
I think we started off not using it, then we forgot and some sentences with it crept in.
We had a discussion on whether or not to use it. I ended up adding some paragraphs about it to the tips and notes of the "to/for" unit which teaches -vaD.
So for now it's kind of in, even if it wasn't planned that way originally, but it might end up coming out at some point if someone feels up to find and ripping out the "offending" sentences.
For what it's worth, I think it's a good idea to keep it in. Thinking more on one of David's earlier posts, I don't think of the "prefix trick" as a "trick" at all. If you start from the idea that Klingon grammar does not have a strict separation of "direct" from "indirect" objects, but rather just "objects", then if a verb happens to have two objects, one first or second person and one third person, you potentially have a choice of prefixes. "Give me a beer!" can thus be either HIq HInob! or jIHvaD HIq yInob!.
In fact (as is now pointed out in the Tips & Notes), this really isn't so different than in English, where we can say either "GIve me a beer!" or "Give a beer to me!". The basic meaning is the same but there may be a difference in emphasis or nuance.
I'll let the experts comment further, but I have been thinking that HIq HInob! is like the English "Give me a beer!" and jIHvaD HIQ yInob! as "Give a beer to me!".
In fact, it is possible to use a prefix which agrees with an unstated first or second person beneficiary object (an indirect object, as you say) instead of the recipient object (a direct object, as you say). Klingon speakers often call this the "prefix trick". HIqem can mean either "Bring me!" or "Bring to me!"