The COMMON BLOCK DIRECTORY command displays information about all entries or a specific entry in the Common Block Directory. The directory is a table of all named common regions and libraries installed in the system. The general format of the CBD command is: CBD [common-region-name [/TASKS]] common-region-name The name of a specific common region. /TASKS Displays the names of each task attached to a specific common region and the number of times the task has mapped to the region (mapping count).