No, not an 000 (zero zero zero) which is a British size of model railways, but an OOO (three oes), sometimes written OoO.
I don't know how you pronounce it. Oh-oh-oh I should imagine.
An OOO is an out-of-office message, usually seen appended to an automatically generated email reply.
They used to say something like:
Thank you for your email. Sally will reply when she is back in the office on the 10th of August. If your message is urgent please contact firstname.lastname@example.org.
Now, however, out of office messages have a sad habit of saying something like:
Thanks for your email, but Sally is on holiday in the remote and beautiful Himalayas. I hope to brush up my Kusunda language skills and bag a few peaks while I'm there!
Thanks for sharing that, but I'm in the LA sunshine at the moment working on the film script for the high-budget blockbuster soon to be made of my best-selling picture book Puffy the Prawn.
...thereby generating murderous feelings in all correspondents.
Perhaps the most smug and irritating of these messages do actually deserve to be called OOOs.
But Out of Office is much easier to say, hear, and understand, all the same.
Word Not To Use Today: OOO. These letters stand for Out Of Office.