Well, there you go Margaret. It never occurred to me to look under Open, as I just assumed that would talk about opening .3dm files in Rhino - not opening Rhino itself. You do realize I am talking here about the Windows command line or it's analog in the desktop Rhino icon's properties, not Rhino's own command line, don't you? I may not have been real clear on that. ....Now that I've checked the help under Open, I realize that you did indeed misunderstand me.
As to what I looked for: in the help I just scanned down the contents, clicking to expand any topic that remotely looked like it would have anything to do with my search. Similarly with the wiki and FAQs.
A topic like "Starting Rhino" or "Opening Rhino" would be great.
I know that your focus in thinking about the help is on how to do things in Rhino - but you seem to have completely overlooked the fact that in order to do anything at all in Rhino, you need to be able to start it up. I'm teasing you here, of course, but there are some startup options for Rhino and I think they should be enumerated under a heading like I've suggested. I know the "safe mode" is described elsewhere in the help, but I think the topic heading I've suggested would serve as a useful conceptual "master node" in the help index - what to do before you do anything else. I also think some more details about the safe mode could be included about whether plugins can be loaded by the user after opening in safe mode with no plugins, whether it's just user plugins that are skipped, etc, etc.
There are folks who like to "think before doing", or in other words "read the help before trying and erring", so more verbiage about what the safe mode is for, what it does and what the user can do with it couldn't hurt.
Also - are there any other startup options that users might find useful? The proposed topic would provide a good placeholder for any new ones that may come up, too. For instance, Dale Fugier suggested it would be possible to allow each user to have multiple named start up configurations. I don't know whether he put it on the wish list, though.
As to the file list: it probably would be most useful if the first sort was on the directories that Rhino puts files in (all of them, including Windows system directories), with a description of the types of files that each directory is intended to hold. Then a list of the specific Rhino-installed files in each. The file list would serve as a customer reference checklist of what should be in the directory to see if any are missing, as well as an indication of what shouldn't if he's trying to see if any rogue files have shown up. The directory purpose description should include suggestions about what types of user files could be added to each, or McNeel's recommendation that no user files be placed in a specific directory. This section should probably mention in general what kind of information is kept in the registry in order to answer the user's curiosity about "how do it know" about all the things he used the last time and the way he's set up the options. Certainly no need to get very detailed here, except to list the categories of info that go in the register.
That's my story and I'm sticking to it.