May sound trivial, but I am Just trying to better understand what the SHARED option does in the USE command.

It seems to me that the SHARED option is already embedded in USE command, since I can USE a file across a network already, without having to specify the SHARED option. Almost all the tables I open in a Multi-User environment don't have the SHARED option, and they are all open across the network, no problem.

So my question is, what are the trade offs of using the SHARED option in a USE command ? - What do I lose?, what do I gain?

Here's why I need to know. Only in one part of the code where I am centrally recoding "The last issued serial #', I have a
USE table IN 0,
command, and in a multi-user environment sometimes they get the error
Error: File is in use by another user.

So, I am trying to figure out, how can I eliminate this error?
Thanks for your help.