In the case of source filters, the UA A&C Server is free to provide any appropriate, Server-specific value for SourceName. There is no expectation that source Nodes discovered via browsing can be matched to the SourceName Property of the Event returned by the UA A&C Server using string comparisons. Further, the A&E COM Client may receive Events from sources which are not discoverable by following only HasNotifier and/or HasEventSource References. Thus, source filters will only apply if the source string can be matched to the SourceName Property of an Event as received from the target UA A & C Server. Source filter logic will use the pattern matching rules documented in the A&E COM specification, including the use of wildcard characters.