This read-create INTEGER specifies whether a Voice URI class matches sip: URIs (RFC 2543) or tel: URIs (RFC 2806), and this type cannot be changed once the class is created. Administrators use it to define the URI schema a given voice URI classification rule is meant to match against, which determines which of the SIP- or TEL-specific pattern objects apply to that class. For example, an admin building a dial-plan rule that classifies calls based on a tel: URI's phone number pattern would first create the class with this object set to tel(2).