1. A method for analyzing a document based on the document content, the method comprising: loading a set of rules into a document editing application, the set of rules defining a set of confidential expression patterns; analyzing a document to determine the existence of one of the set of confidential expression patterns in the document; and in response to the detection of one of the defined set of confidential expression patterns in the document, displaying a visual indication of the detection of one of the defined set of confidential expression patterns.