How to create a view that lists the domains in Firebird 2.5?

I apologize and hopefully you will bear in mind that I have little experience with firebird.

The correct SQL is:

CREATE OR ALTER VIEW "Domains"( "Name" )
AS
select distinct
                        RDB$Field_Name
from
                        RDB$Fields as Fields
where
      substring (Fields.RDB$Field_Name from  1 for 4) not in ('IBE$', 'MON$', 'RDB$')
order by
                 Fields.RDB$Field_Name

However, I find it somewhat confusing that in the RDB $ Fields table, the RDB $ Field_Name field encompasses both the "Fields" themselves and the "Domains."