For the annals of words that mean the opposite of themselves

[dr_whom]

I saw a poster today for the Swarthmore Queer Union that said that the SQU is "closed to queer students". I had to think about it for a decent fraction of a minute (passing through 'well, that's an odd policy for a group calling itself the Queer Union' on the way) before I realized that what they meant was that it's actually closed to everyone except queer students, but open to queer students.