Welcome to MTTags.com. Hopefully, you'll discover that this a really easy place to find information about Movable Type Template Tags. If you think we could be doing something better, please let us know! If this is your first time here, be sure to stop by the information desk, because we've got a growing todo list that might already include what you were about to suggest.
Used in the search result template to pass the IncludeBlogs parameters through from the search form keeping the context of any followup search the same as the initial search.
For example:
<input type="hidden" name="IncludeBlogs" value="<$MTSearchIncludeBlogs$>" />