37.3.3 Command-line argument input ...

The input ... argument(s) specify input file name(s) or complete path(s); wildcards are acceptable. If a path or file name contains spaces, surround it with double quotes; for example:

dcl -f HTML "C:\My Documents\some.mif"

When you specify suffix C, I, or B for the -f switch, the input file must have extension .lst; see §37.3.1 Command-line switch -f format.