Tone of voice
We should be sensitive to the expectations of existing users of the specific site. If we add a BBC presence, we are joining their site rather than the opposite. Users are likely to feel that they already have a significant stake in it. When adding an informal BBC presence, we should “go with the grain” and be sensitive to user customs and conventions to avoid giving the impression that the BBC is imposing itself on them and their space.
For example, we should respect the fact that users on site X are not our users; they are not bound by the same Terms of Use and House Rules as we apply on bbc.co.uk. Attempts to enforce our standard community rules on third party sites may lead to resentment, criticism and in some cases outright hostility to the BBC's presence.
This is not to say that behaviour likely to cause extreme offence, for example racist insults, should be tolerated by the BBC on a BBC branded space on a social networking site. It should not. Neither should behaviour which is clearly likely to put a child or teenager at substantial risk of significant harm. But where we do decide to intervene, we will normally need to do so with a light touch, sensitive to different expectations and a different context from bbc.co.uk.