1. A method of processing order sets, the method comprising: providing for display on a user terminal a content editor user interface configured to enable a user to create or edit an order set; receiving, at a computer system, a user selection of a target format to which the order set is to be exported; determining that the user has included a quantity of section levels exceeding a first level limit associated with the target format; and at least partly in response to determining that the user has included the quantity of section levels exceeding the first level limit associated with the target format, providing a corresponding notification to the user and an indication that the order set is not ready for export; detecting, by the computer system, a user edit with respect to the order set in real time; accessing, by the computer system, at least a first validation rule from memory storing a plurality of validation rules, the plurality of order set validation rules include one or more mapping rules for mapping terms in a source catalog to terms used by the user selected target format; accessing, by the computer system, a first version of the order set without the user edit; applying by the computer system, in real time, the user edit to the first version of the order set to generate an edited order set; applying by the computer system, in real time, the first validation rule to the edited order set to obtain a validation evaluation indicating whether the edited order set is ready for export to the target format; based at least in part on the validation evaluation, providing by the computer system in real time, a corresponding validation notification for display via the content editor; and after determining that the order set is ready for export, exporting by the computer system the order set, including at least one user edit, to the user selected target format.