SUBQUERY Argument
A subquery is a saved search file (*.search-ms) that that you can use as a filter for a new query. The results of the subquery are used as the source for the new query. For example, let's say you have several saved search files that restrict a query by email distribution list: mydepartment.search-ms, teamproject.search-ms, and corporatewide.search-ms. Using the subquery
argument enables you to limit email searches to any or all of these saved searches.
Example
search-ms:query=vacation&subquery=mydepartment.search-ms