2.9.34 Cid

The Cid structure is a command identifier—a 4-byte structure that specifies a command. This element is used in other structures to identify a particular command to be executed.

The 3 least significant bits of the first byte of the structure together form a Cmt value which specifies the command type; the whole structure MUST be interpreted according to this command type, as follows.

Value	Meaning
cmtFci	This structure is a CidFci.
cmtMacro	This structure is a CidMacro.
cmtAllocated	This structure is a CidAllocated.
cmtNil	Specifies that the command identifier is empty and does not specify a command. If the first 3 bits of this command identifier are cmtNil, the value of the entire command identifier MUST be 0xFFFFFFFF.