1. A computer-implemented method of documenting and displaying an indication of a rule used to determine a value for entry in a field of an electronic document, the method comprising: receiving a first value that a user enters under guidance of a graphical user interface, the first value entered for association with a first input field of a document; accessing a rule, from a plurality of predefined rules stored in an electronic storage device, the accessed rule selected based on the rule having been assigned to the first value, each of the rules specifying a respective procedure for obtaining a determined value based on a specific entered value; determining, using the received first value and the procedure specified by the accessed rule, a second value to be automatically associated with at least another input field of the document in response to receiving the first value, and associating a name of the accessed rule with the second value; storing, in a database record associated with the document, (i) the received first value, and (ii) the determined second value with the associated name of the accessed rule; and displaying on a display device a determination information overview regarding the document, the determination information overview indicating the first value as having been user entered, and indicating the second value as having been determined using the accessed rule assigned to the second value; wherein the first value, the second value, and the name of the accessed rule assigned to the second value are displayed following an access of the database record associated with the document to retrieve the stored first value and the stored second value with the assigned name of the accessed rule; wherein the procedure for obtaining a determined value using an entered value further includes using master data accessed from an electronic storage location, the master data being different than the received first value, and wherein determining the second value includes using both the received first value and the accessed master data.