F = mandatory fixed length parameter; V = mandatory variable length parameter; O = optional parameter of fixed or variable length; - the length of the parameter.
For each message type, type F parameters and the pointers for the type V parameters must be sent in the order specified in these tables. The routing label and circuit identification code fields, which are transmitted ahead of the message type field if required, are not shown. Parameter names, pointers to mandatory variable fields and the optional part, and length indicators appear in the m essage in accordance with Figure 3 and are not shown explicitly in Tables 21 to 50.
Reserved (used in 1984 version, Red Book) 0 0 0 1 0 1 0 0 0 0 0 1 1 0 0 1 0 0 0 1 1 0 1 1 0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 Reserved (used in 1988 version, Blue Book) 0 0 0 1 0 1 1 1 Reserved (used in 1992 version) 0 1 0 0 0 0 0 1 0 1 0 0 0 0 1 0 Reserved for future extension 1 0 0 0 0 0 0 0