File with a .REM extension contains a coded file of different content (image or music), stored by a Blackberry phone. The extension indicates coding of the content of a file and is often comprised of a part defining the type of data, for instance - .JPG, and the .REM extension after it.

REM files can be copied on a computer with a specific BlackBerry RIM software, although they cannot be opened directly with Mac OS or Windows. The multimedia files coding functionality is available in the advanced menu of the phone; after turning it off, they can be copied onto a PC and opened like a standard file. The decoding process can be performed only on the Blackberry phone.