While disassembling the enhanced CP/M directory program "LS.COM" to look for a way to put a space between an eight character file name and its extension, I ran into the fact the the program supports a number of command line options.
The command options are preceded by a $. For example:
A0>LS $UV
U - Show files from all user numbers
V - Verbose mode, include user number and attributes
S - Include system (hidden) files in the output
F - Show file names only (no sizes)
P - Pause and paginate output, on by default, use NP to disable
N - Negates all flags that follow
Mike