From OpenSCADAWiki
The grouping request "CntrReqs" is processed at the API level of the node and does not require separate processing in the user code. In fact, into the tag "CntrReqs" may be placed any other requests with the possibility of hierarchical grouping by including of the internal tags "CntrReqs". The only attribute of this tag is the attribute path, which indicates the path to the node and is the basis for internal requests.