Added help for rexx_star. I don't think doZeroData and doDead are commands that ship with SlickEdit. I couldn't find them.
Dashes vs underscores: Emacs implementations do this as well (dash on command line/text docs but underscore in source code). Dashes are more readable (especially with some fonts!) and easier to type. In source code, underscores are always used to avoid the ambiguities with mathematical minus sign. From the command line, you can use either. When looking in the on-line help, always use underscores. Arguably, all commands could just never use underscores and use mixed case words (i.e. NextWord) but underscores/dashes are more readable (simulate a space to the eye). At this point, it's unlikely we will ever change this because it would frustrate many customers who are used to how this works now.