Editing Job Control Language (section)

===Keyword parameters===
<syntaxhighlight lang="jcl">
//NEWFILE DD DSN=MYFILE01,UNIT=DISK,SPACE=(TRK,80,10),
//           DCB=(LRECL=100,BLKSIZE=1000),
//           DISP=(NEW,CATLG,DELETE)
</syntaxhighlight>
All of the major parameters of OS JCL statements are identified by keywords and can be presented in any order. A few of these contain two or more sub-parameters, such as <code>SPACE</code> (how much disk space to allocate to a new file) and <code>DCB</code> (detailed specification of a file's layout) in the example above. Sub-parameters are sometimes positional, as in <code>SPACE</code>, but the most complex parameters, such as <code>DCB</code>, have keyword sub-parameters.

Positional parameter must precede keyword parameters. Keyword parameters always assign values to a keyword using the equals sign (<code>=</code>).<ref>Ashley and Fernandez, ''Job Control Language'', pp. 13–15.</ref>