Thankfully some people at the BBC are still quite helpful with transparency issues, so I was eventually able to find out a bit more about the BBC policy relating to the Gifts and Hospitality Register (see blog dated 4th June 2013) - more precisely what is and what isn't acceptable
Here is a quote from the BBC Policy, as it affects senior managers:-
Receiving hospitality or gifts from organisations or individuals
39. Whilst modest hospitality is an accepted courtesy of a business relationship, the recipient should not allow a position to be reached whereby its acceptance might be deemed by others to have influenced a decision or lead to potential allegations of conflict of interest. Invitations to modest corporate entertainment events may be accepted if there is clear benefit to the BBC e.g. to build supplier relationships or to network with other customers / contacts. Invitations should not be accepted if the event is overseas or includes an overnight stay. Invitations which include partners may be accepted, with line manager approval, and provided they meet the above criteria, if there is no cost to the BBC.