Available command-line help differs for the different command sets.

Command Set Available Command-Line Help
vicfg- commands

Run <vicfg-cmd> --help for an overview of each options.

Run Pod2Html with a vicfg- command as input and pipe the output to a file for more detailed help information. 

pod2html vicfg-authconfig.pl > vicfg-authconfig.html

This output corresponds to the information available in the vSphere Command-Line Interface Reference.

ESXCLI commands

Run --help at any level of the hierarchy for information about both commands and namespaces available from that level.

DCLI commands

Run --help for any command or namespace to display the input options, whether the option is required, and the input option type. For namespaces, --help displays all available child namespaces and commands.

Run dcli --help to display usage information for DCLI.