Apparently, the order in which the Outlook Categories list will display characters is:
- ‘-!”#$%&()*,./:;?@[\]^_`{|}~+
- 0123456789
- abcdefghijklmnopqrstuvwxyz (case insensitive)
I understand this to mean that categories starting with a “!” character will be displayed before those beginning with a “@”, and that these will appear before categories that start with alpha-numeric characters.
I found this out in a commet to an article at another blog.