Board Thread:The Panopticon/@comment-24894325-20170121220436/@comment-1789834-20170123065424

Could you possibly give me a brief explanation of how Mycroft and Sherlock are DWU characters? In The Snowmen, the Doctor's aware that Sherlock is a fictional character? So their appearances as real characters... are they from the fictional universe, or are they characters called Mycroft and Sherlock in this universe?