Provided are techniques for finding content on computer networks. A search request having search terms is received. The search request is executed against an index to identify first search results, wherein the index comprises mappings of search terms to web sites and mappings of search terms to patterns. In response to determining that the search request failed based on first search results, an unknown search term in the search terms that does not exist in the index is found. The unknown search term is matched to a pattern of a similar search term using the mappings of search terms to patterns. A candidate web site is identified based on the matching. Additional content is requested from the candidate web site for the unknown search term to identify second search results comprising previously hidden content. The additional content is indexed.