Thanks for starting off these threads.
1. UK
Just to let you know, these are the rules for including "British", "of the United Kingdom" etc in a company name:
http://www.companieshouse.gov.uk/about/gbhtml/gbf2.shtml#three
As was said, there are no restrictions for using "UK"
2. Using Limited
As someone said, certain Companies Limited by Guarantee do no have to use "Limited" in their name. The guidance notes are here: http://www.companieshouse.gov.uk/about/gbhtml/gbf2.shtml#four and it would appear that we would qualify.
However, we could still use Limited if we wanted to. Personally I see "Limited" a positive, because people recognise us as an incorporated organisation and see this as more substantial that an unincorporated association. Some charities think the word gets in the way of their name (e.g. Barnardos (http://wck2.companieshouse.gov.uk/bbc8991feba3d58c916b352c6362c2db/compdetai...)) so chose not to.
3. Name
As someone said, the legal name doesn't really matter because we plan to operate as "Wikimedia UK" once we have license to do so. We need to pick one that isn't already in use (see http://wck2.companieshouse.gov.uk /bbc8991feba3d58c916b352c6362c2db/companysearch?disp=1&frfsh=1223029936#result) and I suggest something that's simple and descriptive.
I like Wiki UK Limited, and would also be happy with Wiki Information Network Limited
Regards,
Andrew