1. A method using a computer-based machine configured with a rules engine for governing data entry into a database for storing sets of data, each set of data is associated with one of a plurality of entities, each of said plurality of entities having data rules that may vary according to entity, said method comprising: receiving, by a first computer-based machine configured as an application server that includes a web application and a rules engine, a request to enter a set of data into said database; searching a rules base stored on a second computer-based machine configured s a rules base server, said rules base comprising a plurality of documents, each of said plurality of documents being one of a rules interface and a rule, said rule comprising a rule name and a logical operation that returns a rule result indicating whether data comprised within said set of data is valid according to said logical operation, and said rules interface comprising a rules interface name and one or more call names consisting of one or more rule names and rules interface names of other rules interfaces and rules to be called upon execution of said rules interface, and wherein said rules interface names identify at least one of an entity corresponding to the entity associated with said request and a type of data to be entered; and compiling a result comprising a plurality of said rule results, said result indicating whether said set of data is valid according to requirements applicable to said entity; and wherein said step of searching said rules base comprises recursively calling a document; evaluating whether said called document is a rules interface or a rule; and if said document is a rules interface, calling said call names comprised within said rules interface; and if said document is a rule, executing said logical operation comprised within said rule; said step of searching completed when all rules applicable to said entity according to said rules interfaces have been executed.