parv++ has it right: If you have a clear subject line, and prefix it with "OT:", few people are going to complain. I can't speak for others, but the times I get annoyed about OT nodes are when the subject line suggests an interesting perl question, when the body contains something completely different. It's much easier to ignore posts you don't care about or can't answer if properly labeled.

If the world were a perfect place, I'd love to off-topic nodes titled something like "OT (Windows): How to schedule a job?" or similar, so I have a reasonable chance of selecting appropriate nodes to read.