User manual text for multiple users

[Willem Ferguson]

Below is some proposed text in the user manual for this topic. Please 
review because my understanding may be erroneous.

---------------------------------------

== Several users of _Subsurface_ on one desktop computer
A frequent need is for two or more persons to use _Subsurface_ on the 
same desktop computer. For instance
members of a household may use the same computer. There are two 
approaches for doing this.

- If the different users of a desktop computer do not log onto the 
desktop/laptop under different user names
   then the simplest way is for each person to use her/his own divelog 
file within Subsurface. In this case John
   would work with the _Subsurface_ file _johns-divelog_ and Joan would 
use _joans-divelog_. Each user would select
   the appropriate dive log by selecting, from the *Main Menu*, _File -> 
Open logbook_ and then select her/his own
   dive log file from the list of files lower down in the menu.
- If the users log onto the same computer using different userIDs (i.e. 
users each have a separate user space),
   the desktop, accessible software and usage permissions are likely to 
differ from user to user. In this case
   it is possible to launch _Subsurface_ and specify which user is using 
the software. From the command-line
   one can launch _Subsurface_ with the option --user=****, where **** 
is the userID of the person wishing to
   launch _Subsurface_. An example would be the command:

   _subsurface --user=John_

    This process can be facilitated by creating a link/icon that is 
specific for a user, e.g.
   _Johns-Subsurface_ and  _Joans-Subsurface_.

---------------------------------------

In a Win environment the config settings for Subsurface would reside 
inside the user space for a specific user: other users would not be able 
to see my Subsurface config settings. Is this correct? If so, what is 
the advantage of using the --user= command-line option?

In a Linux or Mac environment, I suspect much the same would apply?

Please explain in a bit more detail the exact use of this command-line 
option. My vision on this is a bit muddy because I have never worked in 
a truly multi-user environment. The only users on my equipment are 
myself and root.

Kind regards,

willem