There are a few rules regarding page names:

* Page names cannot be empty
* Page names cannot start with a `.` nor `^`
* Page names cannot contain `@` or `$`, due to ambiguity with referencing specific positions or anchors inside a page
* Page names should not contain `!`
* Page names cannot end with a _file extension_ containing just letters. That is, a page name like `test.md` is not allowed, whereas `test.123` would be.