1. An information retrieval system, the system comprising: at least one database storing a plurality of documents; a data structure caching a uniform resource locator for a document predefined to be relevant to at least a portion of a taxonomy; and a server coupled to the at least one database and the data structure, the server configured to: select the taxonomy for a query received from an application presented by a client access device based on provenance of the application; process the query against the at least one database using at least one content-based search engine to generate a search result that identifies at least one document relevant to the query according to a ranking order; extract the uniform resource locator for the document predefined to be relevant from the search result if the uniform resource locator exists in the search result; associate at a position of the ranking order in the search result the uniform resource locator for the document predefined to be relevant to the at least a portion of the selected taxonomy; and return the search result with the associated uniform resource locator for the document predefined to be relevant to the client access device.