Is it possible to have a file shared between branches?

Hello,

Is it possible for git to track a single file that would be shared accross branches? Case in point: a to-do list file that describes what has to be done in all the branches; it can be convenient to put all the things that have to be done in a single, shared file, while keeping this to-do list in sync with the code (so that it lists what has been done, and what remains to be done). Committing in a branch would in effect also commit the shared file in the other branches (another possibility may be to have in effect many "trees" in a single git directory, with a specific tree for the to-do list).

Is this something git can do?

EOL