 Numerous Blackberry models allow this feature by using the ALT key when pressing a key to select the letter, and not the number on the key.On older landline telephones, the O, Q and Z sometimes vary in placement or are omitted entirely; this is not an issue for most mobile telephones as all 26 letters must be provided to support short message service transmission.The dialing of 1 or 0 instead of I or O in phonewords can lead to misdialed calls; one such typosquatting incident targeted 1-800-HOLIDAY (+1-800-465-4329, the toll-free direct reservations line for Holiday Inn) by subscribing 1-800-H0LIDAY (+1-800-405-4329, the same number with 'o' replaced by 'zero') to a rival vendor which stood to collect a profitable travel agent's commission.