There are quite a few Hiltons in the Metro DC area, but I believe that the Twinbrook is the only one in Rockville MD.
I'll go by your word. Having been an auditor, I needed to "confirm", since the CAF's people's link (email) led me to Twinbrook, and I checked Hilton's site and they only used Hilton. I sort of asked CAF, but the person answering me was not answering/confirming, just beat around the bush, didn't CONFIRM that they're the same. Oh, I called also, but the female person at the other end was like "clueless", couldn't say anything about "Twinbrook" either.... Such a simple thing isn't it, and I made it difficult. Guess "Twinbrook" is an archaic word.