Rules and recommendations for using system symbols

The general rules and recommendations for using system symbols (which are described in z/OS MVS Initialization and Tuning Reference, SA23-1380) also apply to JES2 commands. The following are exceptions to those general rules and recommendations:

Use at least one blank:
When you enter a JES2 command that contains system symbols, you must code at least one blank or comma before the first system symbol occurs. Otherwise symbolic substitution does not occur for the system symbols in the command.
For example, symbolic substitution occurs in the following command, which specifies a VTAM® application identifier of jes, because a blank appears after the $e character string and before the &SYSNAME system symbol:
```
$e logon(1),a=jes&SYSNAME.
```
If the command is routed to two systems named SYS1 and SYS2, the following are the results of symbolic substitution:
```
$e logon(1),a=JESSYS1     /* Command entered on system SYS1  */
$e logon(1),a=JESSYS2     /* Command entered on system SYS2  */
```
However, symbolic substitution does not occur for the following valid command, which does not include a blank or comma before the &SYSNAME system symbol:
```
$DJ'&SYSNAME.'  /* Substitution does not occur for &SYSNAME! */
```
Use the MVS™ ROUTE command to route a command:
If you want to route a command on one member to be processed on another member in a MAS, use the MVS ROUTE command instead of the JES2 $M command. For details on how to use the ROUTE command, see the description of ROUTE in z/OS MVS System Commands, SA38-0666.
Use double ampersands with the $N command:
If you use the $N command to route a command to another node in a network, or if you enter a command from a workstation that is attached to an RJE line, use double ampersand (&&) notation to cause substitution to occur on the receiving node.
For example, to enter a single JES2 command from another node in a network to specify unique offload data set names for three local members of a MAS(SYS1, SYS2, and SYS3), enter the following command from the remote node:
```
$N,D=targetnode,'$t offload1,dsn=&&sysname..offload'
```
When the command reaches the target node, JES2 substitutes text for &SYSNAME as follows:
```
SYS1.OFFLOAD on system SYS1
SYS2.OFFLOAD on system SYS2
SYS3.OFFLOAD on system SYS3
```
For more information about using double ampersand notation, see z/OS MVS Initialization and Tuning Reference, SA23-1380.
Restriction:JES2 commands containing system symbols, which enter the system through card readers, are not translated.