included link points, not to a client IP or direct source, but to a source cache which stores the IPs of other clients contacting it to download the same file. Once a client connects to the cache, it is served IPs for alternate sources, while its own IP is stored within the cache and forwarded to the next one connecting to the cache. This system operates similar to a BitTorrent tracker. xs=http://cache.freebase.be/[ SHA-1 hash ] Reference to an eD2k source xs=ed2kftp://[client address]:[client port]/[ed2k hash]/[file size]/ Supplement format (x.) For experimental and self-complementing informal options, the prefix followed by a chosen suffix letter can be used. These names are guaranteed to never be standardized. x.[name of the new parameter]=[data of the new parameter (URL encoded)] Clients See also BitTorrent Burnbit ed2k URI scheme InterPlanetary File System Metalink Named data networking Peer-to-peer Explanatory notes References External links , an early definition of the format (last update 2002) CHK Freeware checksum utility with SHA1-Base32 and ED2K support , an open source command-line tool, which can calculate magnet links File sharing URI schemes