Ideally, it should have a name and should not replace the one that already exists. Paratext should only show the most recent version when starting progress for a project. Not replacing it also means that Paratext can more easily automatically update any previous version of the plan to the new version (e.g. as shown in this video).
Note for the developers of a project plan:
- You should ensure that the plan ID has not changed from one version to the next.
- You should ensure that the ID of all stages and tasks are the same.
- Make sure the plan version number is set in the file.
- Ideally, you used (Hold Shift) Paratext > Support and development > Base project plans to create the new version. If you didn’t know this existed, it is likely too late to work with it now.
See this post for more information on creating plan updates.
EDIT: It appears having a different name isn’t as important to the automatic update process as I originally thought and that the version number actually becomes part of the plan ID (so it’s {ID}_{Version}).