You use the fq parameter to filter the documents that match the search
criteria specified with the q parameter without affecting the
relevance scores of the documents included in the search results. Specifying a filter just controls which
matching documents are included in the results, it has no effect on how they
are scored and sorted.
The fq parameter supports the structured query syntax described in Search API.
For example, you could add an available field to your documents to
indicate whether or not an item is in stock, and filter on that field to limit the
results to in-stock items:
search?q=star+wars&fq=available:'true'&return=title
