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.
The G3 format is used to compress image files in TIFF format when sending faxes. The compression algorithm allows for the use of a standard 10-times compression, which can be increased. It is used to remove excess image data, which makes it possible to reduce the size of the image and speed up delivery.