In COBOL and PL/I, the translator can set the value of particular lengths. This means that they are optional in programs that specify data areas.
In C, C++ , you must specify all LENGTH options, except on the SEND MAP, RECEIVE MAP, READ, READNEXT, READPREV, REWRITE, WRITE, DEQ, and ENQ commands.
If you use the ENQ command without a LENGTH option, CICS® assumes that the command is applied to an address (for example the CWA). If you use the ENQ command with a LENGTH option, CICS assumes that the command is applied to a name (which can be 1 through 255 bytes long).
When a CICS command includes the LENGTH option, you generally express this option as a signed 16-bit binary value (the command description tells you what the value should be). This places a theoretical upper limit of 32767 bytes on LENGTH. In practice (depending on conventions of recoverability, function shipping, and so on) the achievable upper limit varies from command to command, but is somewhat less than this theoretical maximum.
The FLENGTH option, where available, allows you to specify any length value up to 2048 MB, but for application portability, it is recommended that you do not use more than 24 MB. Some commands have limits that are significantly below this. For example, RECEIVE and SEND have a limited FLENGTH of 32767 bytes.