Integrated Timeline

From MU

Some historical MU characters come from non-Trek related stories, but did not come from a separate timeline. Instead, their universe has been integrated into the MU timeline.

It is extremely difficult to pull this off without creating paradoxes. For example, the events in the Babylon 5 storyline preclude the events in the Star Trek timeline from occuring. Despite this, the MU timeline contains events from both histories, and even integrates certain events from Battlestar Galactica.

You should not attempt to integrate a timeline from a non-Trek story into the MU timeline without ensuring there will be no paradoxes. When in doubt, use a timeline transplant instead.