Broadcasting the Live 8 concert on Saturday was a giant test of the BBC's impartiality.
The BBC received hundreds of complaints about swearing during the Live 8 concert
Unlike Live Aid 20 years ago, which was specifically organised as a charity event, Live 8 had distinct political overtones.
But the BBC is required by its charter to be impartial, and cannot be seen to promote any view or project on matters of political or public policy. It certainly cannot be seen to endorse the Make Poverty History campaign - the rallying cry for Live 8.
So the BBC was in the strange position of covering the event while trying to maintain its distance from it. Special guidelines were issued reminding programme-makers of the corporation's position.
The guidelines said:
The BBC is not organising or running Live 8 but is the major broadcast partner
The BBC cannot present one solution to world poverty
The BBC cannot host any activity campaigning specifically for Make Poverty History
At no point can presenters or BBC people encourage listeners and viewers to lobby, march or campaign to take direct action
All interviews, while reflecting the unique nature of the event, must maintain the BBC's editorial values
Presenters should not appear on stage as performers/part of the event
When describing Live 8 and its aims, BBC people should avoid saying 'we' and instead should use 'they' or 'the organisers'
The BBC will not run built trails for the concert ticket number but will mention it where editorially relevant within programmes
The big screens that will show the concerts at sites around the UK cannot be promoted as rallying points and the BBC and its local authority partners have the right to cease coverage if there is any threat to public safety
All the BBC networks were asked to build in appropriate pieces of context and explanation in the run-up to the event and on the day itself.
Nick Vaughan-Barratt, the BBC executive editor in charge of the Hyde Park outside broadcast, said it had been a bit like covering a party conference. The idea was to "let the audience see the proceedings unadulterated and then have a discussion about them."