If you know well enough to think "Hey, I should title this as Offtopic: whatever", then it probably doesn't belong here. HN has been around long enough that pe

If you know well enough to think "Hey, I should title this as Offtopic: whatever", then it probably doesn't belong here. HN has been around long enough that people should be able to have a decent feel for what's on-topic and what's not; and if they're mistaken the flag button is there. What I think is on-topic may not be what the next guy thinks is on-topic. The definition of what is on-topic is defined by the community (by way of voting and flagging). My personal litmus test is whether I think a link is relevant to a hacker / entrepreneur. To be fair, not all of my submissions meet my own criteria, so clearly there's gray area there. I just don't want to encourage people to increase the noise when it's already tough enough to deal with it and maintain the health of the community.