www.alphadictionary.com

Do you find this construction problematic? I’ve seen it numerous times.
I have an example from an e-book at hand, if you’d like to see it.

Xxxx . . . xx (xxx . . . . Xxx).

In other (well, actual) words, a full stop and new sentence within a parenthesis.

Can't say as I quite get what you're getting at there, though I DO have a problem with how RSVP is used these days. It seems most folks nowadays take it to mean only 'tell me if you're coming', not "Please Respond". I've seen RSVP buttons on e-vites that only allow for a positive response, which isn't what it means. GRR.

I think this sentence is an example of what brogan is talking about
(but I'm not sure. I could be wrong).

I think the choice of "RSVP" as the title for the subject is misleading. "RSVP" per se is not the intended topic for discussion but a request of Agorans to respond as Slava and I have. As for the layout/publication pattern on which I think brogan has requested comment, I can't say I've noticed it.

Thanks. Your example is spot on. I consider it illogical. A semicolon seems more appropriate.
Your point on the header is taken.

Here’s the passage which brought to mind this cutie from my menagerie of pet peeves:

We’d experimentally demonstrated rapid, adaptive evolution in nature (needless to say, that was the last time I used homemade graph paper to look at preliminary data. In my defense, the differences in leg length among populations, though statistically significant, were small and thus not obvious on a hand-drawn graph).

Improbable Destinies
Jonathan B. Losos

I'll go along with you on that one (it's for sure a silly way to write).