CONCAT
CONCAT is a TSO command. It is used to dynamically concatenate a data set with an existing DDname. The new data set can be added before or after the existing set. Duplicate data set names can be added. It can also delete a data set from within an existing concatenated set. If the data set to be added is not catalogued then a volume and unit can be supplied. The search for the data set can start from the top or bottom of the concatenated set. CONCAT can also be used to test for the existence of a data set within the concatenation. CONCAT runs without APF authorisation and is very suitable for dynamically manipulating concatenated data sets for use with ISPF.