Editing Job Control Language (section)

===Positional parameters===
<syntaxhighlight lang="jcl">
//TLBL TAPEFIL,'COPYTAPE.JOB',,,,2
//ASSGN SYS005,200
//DLBL DISKFIL,'COPYTAPE.JOB',0,SD
//EXTENT SYS005,VOL01,1,0,800,1600
</syntaxhighlight>

DOS JCL parameters are positional, which makes them harder to read and write, but easier for the system to parse.
* The programmer must remember which item goes in which position in every type of statement.
* If some optional parameters are omitted but later ones are included, the omitted parameters must be represented by commas with no spaces, as in the TLBL statement above.

DOS JCL to some extent mitigates the difficulties of positional parameters by using more statements with fewer parameters than OS JCL. In the example the ASSGN, DLBL and EXTENT statements do the same work (specifying where a new disk file should be stored) as a single <code>DD</code> statement in OS JCL.