is a format used in the MobiPocket Reader software on desktop and mobile platforms. Books in this format can have .prc and .mobi file extensions. MOBI was originally based on the PalmDOC format; adding HTML tags made it possible to create a high-compression version which compresses data to a high degree. There are a number of formatting restrictions – the text cannot be indented, and inserted tables and images cannot be formatted.
This format is used to store small personal icons. It is used in website development to create favicons that are displayed in the address bar of the web browser as well as in satellite TV for identifying broadcast channels. It is very similar in structure to a GIF format image.