This command-line syntax uses a variable to show that the user supplies a file name.
It produces this output:
Variables can appear within computer text or computer example listings. This example specifies volume as a variable part of a file name:
The HelpTag software takes your "%%volume%%.htg" file as input.
The HelpTag software takes your volume.htg file as input.
In both of these examples, the %% pairs could have been entered with the long form (<var>...<\var>) or the short form (<var|...|).