Formula formats

case Contact.MailingStateCode
    when 'DE' then 'Mid-Atlantic'
    when 'NJ' then 'Mid-Atlantic'
    when 'NY' then 'Mid-Atlantic'
    when 'PA' then 'Mid-Atlantic'
    when 'MD' then 'Mid-Atlantic'
    when 'DC' then 'Mid-Atlantic'
    when 'VA' then 'Mid-Atlantic'
    when 'IA' then 'Midwest'
    when 'IL' then 'Midwest'
    when 'IN' then 'Midwest'
    when 'KS' then 'Midwest'
    when 'MI' then 'Midwest'
    when 'MN' then 'Midwest'
    when 'MO' then 'Midwest'
    when 'NE' then 'Midwest'
    when 'OK' then 'Midwest'
    when 'WI' then 'Midwest'
    when 'OH' then 'Midwest'
    when 'WV' then 'Midwest'
    when 'CT' then 'New England'
    when 'RI' then 'New England'
    when 'VT' then 'New England'
    when 'MA' then 'New England'
    when 'NH' then 'New England'
    when 'ME' then 'New England'
    when 'AR' then 'South'
    when 'FL' then 'South'
    when 'GA' then 'South'
    when 'LA' then 'South'
    when 'NC' then 'South'
    when 'SC' then 'South'
    when 'TN' then 'South'
    when 'TX' then 'South'
    when 'KY' then 'South'
    when 'MS' then 'South'
    when 'AL' then 'South'
    when 'AK' then 'West'
    when 'AZ' then 'West'
    when 'CA' then 'West'
    when 'CO' then 'West'
    when 'HI' then 'West'
    when 'ID' then 'West'
    when 'MT' then 'West'
    when 'NM' then 'West'
    when 'NV' then 'West'
    when 'OR' then 'West'
    when 'SD' then 'West'
    when 'ND' then 'West'
    when 'UT' then 'West'
    when 'WA' then 'West'
    when 'WY' then 'West'
    when 'PR' then 'Territories of the U.S.'
    when 'VI' then 'Territories of the U.S.'
    when 'GU' then 'Territories of the U.S.'
    when 'AS' then 'Territories of the U.S.'
    when 'MP' then 'Territories of the U.S.'
    when 'AA' then 'Armed Forces'
    when 'AE' then 'Armed Forces'
    when 'AP' then 'Armed Forces'
    else 'Unknown'
end