Thanks for pointing me to the rules, but not for a couple of comments which make it sound like I was trying to get away with something. I don't fly from IAD as a rule, and I certainly don't get to an airport that early with so much time to kiss, as a rule, so I was just passing time more than anything else. I didn't realize I wasn't entitled even to the First lounge as I can't think of a time when I've used a BA lounge without flying on BA, and in those cases, I automatically use First lounge or CCR when available. Same deal for dinner. I didn't really need dinner, so much as I was pretty bored and thought a nice meal would be a pleasant way to pass the time. I don't (and didn't) doubt that the Lounge supervisor was correct, so the only point in posting was to educate anyone else like me who has a loose grasp of the rules. Anyway, now I know.

By the way, SteveinA2 - the dining room was open from 4:30, so I expect that this would accommodate a 7pm flight, but who knows? Maybe it is still intended only for those on the later flight. Best to check with the front desk before doing something silly! As I mentioned, the Lounge supervisor (and her predecessor, who originally signed me in) was very kind and professional.