Question about pulling custom fields from email and field types

RT Users
1

I am creating custom fields that are the “select one value” type in rt
3.4.5. I am reading my tickets in from email and I’d like the email to
be able to populate the custom field. My question is in the email do I
just use the name of the custom field value or do I need to use the sort
number in the list?

Thanks,
-Tim