Replace "Unspecified" with ''

I am building multiple reports on:

-  Service Request object (Picklist Field)

- Contact object (Contact Role value)

If the picklist or Contact role values are blank it fills the value "UNSPECIFIED". We need to replace it with a NULL or '' value.

I tried the following formats but none of them give me the correct answer:

IFNULL("- Role"."Account Contact Role", ' ')

IFNULL("- Role"."Account Contact Role", '')

I tried the following:

CASE

WHEN "- Role"."Account Contact Role" = 'Unspecified'

THEN ''

ELSE "- Role"."Account Contact Role"

END

This does give me the correct results, but is this the correct method?