In the same category are “Sold Out,” when you’ve been been waiting in line at a movie theater for 30 minutes (I know you can get tickets online, but sometimes you’ve decided to go out on the spur of the moment); “Closed for Private Party,” when you’ve been looking forward to a meal at your favorite restaurant all day; “Back in an Hour,” when you’ve come crosstown to buy something you need to have immediately; “Not in Service,” when you’ve been counting on using an A.T.M. or getting a Coke; “Use Other Door,” when you’ve gone around a long block to get to what you thought was the main entrance; “Register Closed,” when you’ve been waiting not-so-patiently behind a fellow customer with 25 items; and “The role of Violetta will be sung by the understudy,” when you’ve spent hundreds of dollars to see Renée Fleming.