@salvatore.riccio
The provider application uses GroupId to efficiently update the state for multiple item streams via a single group status message. GroupId is available in the refresh and status message. It is a RsslBuffer with a maximum allowed length of 255 bytes that contains information about the item group to which this stream belongs.
You can refer to the section 13.4 Item Group Use in the Transport API C Developers Guide for more information.
However, if this question is specific to the Refinitiv Real-Time feed handler, please directly contact the data feed team via MyRefinitiv to answer this question.
