Syntax: a whole number
This controls the default number of results (hits) listed on each results page. When there are more than this many results to a user's query the user will have to hit "next" to see more results.
This number may be overridden by the search user with the rpp
URL/query parameter - up to a maximum of Max User Results per
Page - to allow the search user to customize the number of results
per page.
Note that increasing the results per page can increase the time needed per search, as more information must be retrieved due to more results.