What is required from a certificate point of view for a system?

Here is a Support Article that provides the information you should need for the SMS certificates.

https://softwaresupportsp.aveva.com/en-US/knowledge/details/000033841?lang=en_US

Are you using InTouch Web for your web delivery or Access Anywhere?

If Access Anywhere, the SSL cert configuration is detailed very well in the Access Anywhere Administration Guide. 

We followed that but :
"Every computer in your system requires an IT-generated certificate binding certificate with the following properties."

Does this imply that we would need three different certificates?

What about the 'client' certificate that the user would normally export from the Historian to make the trends working? 

We're using OMI, not InTouch.

For the Web Client to get the correct license (we're using Supervisory Server license) we had to enable Remote Desktop Services on the server...seems dumb.