How to read syntax diagrams

To read syntax diagrams, follow one line at a time from the beginning to the end, and code everything you encounter on that line.

The following conventions apply to all syntax diagrams for DFSMSdss commands:

Read the syntax diagrams from left to right and top to bottom.
Each syntax diagram begins with a double arrowhead (►►) and ends with opposing arrows (►◄).
An arrow (─►) at the end of a line indicates that the syntax continues on the next line. A continuation line begins with an arrow (►─).
Commands and keywords are shown in uppercase and lowercase letters. The uppercase portion is the minimum needed to code the command properly; the lowercase portion is optional. For example, COPYDump can be coded in any of the following ways: COPYD, COPYDU, COPYDUM, or COPYDUMP.
Note: Commands must be entered in uppercase. Lowercase is not recognized.
Some commands and keywords have alternative abbreviations; these appear as part of the stack for that command or keyword. For example, the alternative abbreviation for COPYDump is CPYD.
```
>>-+-COPYDump-+------------------------------------------------><
   '-CPYD-----'   
```
Words in all lowercase letters represent information you supply. For example, volser or ddn.
You must provide all items enclosed in parentheses, ( ), and you must include the parentheses.
Where you can choose from two or more keywords, the choices are stacked one above the other. If one choice within the stack lies on the main path, you must choose a keyword. In the following example you must choose either BLK, TRK, or SOURCE.
```
>>-+-BLK----+--------------------------------------------------><
   +-TRK----+   
   '-SOURCE-'   
```
If one or more keywords are below the main path, they are optional. In the following example CATalog and RECATalog are optional keywords. You can choose one, or the other, or none.
```
>>-+-----------+-----------------------------------------------><
   +-CATalog---+   
   '-RECATalog-'   
```

If a stack of keywords are below the main path and one keyword is above the main path, the use of the keyword is optional, and the above item is the default. In the following example, if no keywords are specified, the default TGTAlloc(SOURCE) is taken.


   .-TGTAlloc(SOURCE)-----------.   
>>-+----------------------------+------------------------------><
   '-TGTAlloc--(--+-BLK----+--)-'   
                  +-CYL----+        
                  +-TRK----+        
                  +-SOURCE-+        
                  '-SRC----'

The repeat symbol is shown below:
```
                  ┌─┐
                  ▼ │
```
The repeat symbol appearing above keywords and variables indicates that you can specify those keywords and variables more than once. If a comma appears in the repeat symbol, you must separate repeated keywords or variables with a comma or any valid separator.

For example, after the keyword BYPASSACS, you can enter multiple data set names separated by commas.
```
                 .-,---.      
                 V     |      
>>-BYPASSACS--(----dsn-+--)------------------------------------><
```

Substitution blocks are used to simplify the diagrams. They indicate that blocks of the syntax diagram are located outside of the main diagram. You insert the keywords for that block where the symbol appears, and return to the main diagram to continue with the command.

In the following example the substitution block, A, points to a block of the syntax diagram that immediately follows the FULL keyword.


>>-RESTore--FULL--+-------+------------------------------------><
                  '-| A |-'


A: Optional Keywords Used With FULL:

>>-+-------------+--+-----------+------------------------------><
   '-CANcelerror-'  +-COPYVolid-+   
                    '-CPYV------'

The above example is equivalent to the following:


>>-RESTore--FULL--+-------------+--+-----------+---------------><
                  '-CANcelerror-'  +-COPYVolid-+   
                                   '-CPYV------'