`Not_Assigned` category?

I’ve submitted this through http://www.unicode.org/reporting.html, but track it here since it affects this repository.

Both http://www.unicode.org/reports/tr18/#Categories as the latest draft of that document i.e. http://www.unicode.org/reports/tr18/proposed.html#Categories list the following example:

\p{General_Category = Not_Assigned}

However, Not_Assigned is not a valid General_Category name as per the table here: http://unicode.org/reports/tr44/#GC_Values_Table

Suggested fix: use Unassigned instead in the example.

\p{General_Category = Unassigned}

It would be easy enough to add a Not_Assigned alias but I’d rather not if this is indeed a mistake.

Compare the General_Category examples in Unicode TR18 with the valid names in the TR44 General_Category Values Table, using the linked sections as the starting point. Done means the example consistently uses the valid category name, or the Unicode report confirms that no repository change is needed.