Token,Description,Reference
unknown,"The number's semantics are unknown.  This        
value is the default in the absence of this
parameter.",[RFC3939]
local,"The number only has meaning within the domain    
of the sending system identified by the
[RFC2822] From field of the message.",[RFC3939]
e164,"The number's semantics are described in [ITU-T Recommendation E.164 (1997), ""The international public
telecommunication numbering plan""].",[RFC3939]