This part of ISO 14915 provides recommendations and requirements for the design of multimedia user interfaces with respect to the following aspects: design of the organization of the content, navigation and media-control issues. This part of ISO 14915 is limited to the design of the organization of the content and does not deal with the design of the content in general. Design issues within a single medium (e.g. the lighting of a film sequence) are only addressed with respect to the ergonomic issues related to user controls. This part of ISO 14915 provides - a framework for the structuring of multimedia applications, - information and recommendations on the design of navigation structures and navigation mechanisms for use within multimedia applications, and - information and recommendations on the design of controls for use within multimedia applications. It does not specifically address entertainment applications, although some recommendations can also be applicable to that domain. ISO 14915 does not address implementation issues. The ergonomic requirements can be realised through very different mechanisms, e.g. the delivery system, a scripting language or the application.