1. A system comprising: a programmer device, including a communication circuit configured to be communicatively coupled to an implantable cardiac rhythm management (CRM) device, and including a user interface configured to program a plurality of parameters used by the CRM device, the user interface configured to interactively display, during a programming of at least one of the parameters: a graphical indication of a changing value of at least one of the parameters as at least one of the parameters is being programmed; and a graphical indication of a rule constraining the value of the at least one of the parameters being programmed.