mv | rename

The mv (alias "rename") command tells fossil that a file has gone from one external name to another without changing content.

You could do this by renaming the file in the file system, deleting the old name from the project, and adding the new name. But you would lose the continuity of the content's history that way. Using mv makes the name change a part of the history maintained by fossil. You will, of course, need a good comment somewhere (say, the commit comment) if you want to remember why you changed the name... fossil only maintains history, it doesn't (yet) explain it.

mv is much like the rm command, in that it manipulates fossil's "idea" of what is part of the project. The difference is that mv assumes you have actually made some change to the file system.

See also: fossil rm, fossil add, Reference