The predefined variables are classified as follows:
CCB Client Control Block variables
MCB Master Control Block variables
PPD Procedure Control Block variables
SSP Physical session variables
TXX Session text/audit variables
In addition, the CURLINE variable always contains the text of the current session line.
A complete list of all variables along with their current values can be obtained at any time with the VarLibrary command. Note that certain variables exist only if a session is present. Further information concerning the variables can be obtained by contacting the marketing agent (see 'Product Information' under Help menu).