TSO/E has defined a number of data set types. If these types fail to meet your needs, you can either change the attributes of the data set types or you can define your own data set types.

For each data set type that you define, you can write a syntax checker and a syntax checker exit. The syntax checker can detect errors when a user edits a data set of the type recognized by the syntax checker. You can use the exit to obtain information that the user specifies on the EDIT command.

The EDIT subcommands, COPY, MOVE, and RENUM all change line numbers or add line numbers to a data set. If the numbering algorithms these subcommands use do not meet your needs, or you wish to change the way these subcommands work, you can write an exit. One exit serves all three subcommands.

If the functions provided by the EDIT command are inadequate, you can supplement those functions. You do this by writing your own subcommand processors and adding them to the system.

The EDIT subcommands, MOVE and COPY, both require the allocation of data sets for work space. Depending on a number of factors, the subcommands use either temporary space or permanent space. You have the option to either preallocate the space or to allow EDIT to allocate it dynamically as it's needed.

For a description of EDIT and its subcommands, see .

For more customization information, see Customizing the EDIT command.