We may struggle here with the terminology a little bit.
If you are asking about the structure of address space inside the OPC server, that is, whether you can define how the OPC server presents its available tags to the OPC clients (the OPC terms would be branches and leaves/items in the hierarchical address space), and basically configure the OPC server through the OPC, then the answer is No. And, this is not achievable through just the standard OPC interface to any OPC client: The OPC specification leaves this task to the OPC server, or proprietary interfaces.
If you are asking about runtime OPC groups (this is what OPC client uses to connect to OPC server), then the answer is Yes: QuickOPC creates runtime groups automatically as needed, and adds items to them according to how your client application wants to Read, Write, or Subscribe to value changes of these items.
I hope this helps.
Zbynek Zahradnik

From: ...
Sent: Tuesday, October 19, 2010 10:14 AM
To: Zbynek Zahradnik
Subject: QuickOPC.NET

Hi,

Can i create groups/tags using QuickOPC.NET or is it purely a data retrieval software package?

Regards,
M.