The Encoded File category encompasses all the files that store data in an encoded format. The encoding can be done through encryption, compression, or even simple text-to-binary. While most file encoding, like encryption, is done for security purposes, encoding is also used to make files smaller in size through compression. There are numerous proprietary encoded formats in use today.
Popular Encoded File Extensions
SPD — Format: Zip
Developed by Samsung, an SPD or an S Note File is a form of compressed, zip file format used by Samsung's S Note, a Samsung-only, note-taking application for the company's Android phones. The “.SPD” file can store the contents of a note which can be typed or handwritten text, drawings, charts, audio, and images and can be exported to many other formats, from image formats like JPEG as well as PDFs. SPD files also support password-protection.
HEX — Format: unknown
The “.HEX” file format is used to store a file in a hexadecimal format and consist of records of data, with the address in memory to store the data at the start.