Earlier (see Project Descriptors), we talked about floating projects (those having a null directory). There might also be times when you want to temporarily relocate a non-floating project (for instance just this once, without modifying the project descriptor). You can relocate a project by calling any of the entry point functions with a prefix of 1 (<C-u 1>).
Since people have a tendency to keep clones under the same umbrella directory, it seems convenient to start prompting you for the relocation directory under the parent of the project's original directory. Patcher does that.
As previously mentioned for floating projects (see Project Descriptors), an interesting side effect of relocation is that it allows you to use one particular project descriptor for another, completely independent project which would happen to use exactly the same set of options.