When opening the document which has some plug-in related data in it, InDesign Server gives an error message (to Event Log) :
"The document XXX.indd uses one or more plug-ins which are not currently available on your system."
This can be skipped on desktop InDesign but is there a way to skip this on InDesign Server? It is 64-bit Win InDesign CS6 Server.
Found out that you can do this in your desktop plugin (what writes the persistent data to the document) by setting missing plugin warning level to "IgnoreTags".