Residency Requirements Of British Research Degrees

Hi,

I think we've all read that British research degrees (M.Phil & Ph.D/D.Phil) can be earned through little or no residency, but most of the programs I've researched seem to require residency. So is this a D.L. legend or does it exist? If anyone out there has, or is in the process of actually earning a research degree, please let me know about your experience.

Thanks