A document using the Adobe InDesign Markup Language extension represents a structured file format. This format packages data compatible with InDesign, a widely-used desktop publishing application. It serves as an alternative to the standard InDesign Document (.indd) format, offering broader compatibility across different versions of the software. Think of it as a blueprint of an InDesign project, detailing the text, images, styles, and layout instructions necessary to recreate the design.
The utility of this file type lies in its ability to facilitate file exchange and recovery. Because it is XML-based, it is less susceptible to corruption than the proprietary .indd format. Opening an older design with a newer version of InDesign can sometimes lead to incompatibility issues. Saving the file in this intermediary format often resolves such issues, allowing users to open and work with the design regardless of software version. This ensures that valuable design work can be preserved and accessed over time, mitigating the risk of obsolescence due to software updates.