One of the references is the rsync protocol (short overview):
- Not directly validated by either ISO, OASIS, W3C, IETF(RFC), ECMA, IEC, but rsync has an official TCP port (873) and there is one RFC on the rsync URI Schemersync URI Scheme. (note that an ISO standard is typically charged 160 USD to be accessed to...).
- Plenty of clients and servers, the reference implementation being the rsync application.
- File synchronization, but no conflict handling
- Bandwidth as low as possible:
The algorithm identifies parts of the source file which are identical to some part of the destination file, and only sends those parts which cannot be matched in this way. Effectively, the algorithm computes a set of differences without having both files on the same machine. The algorithm works best when the files are similar, but will also function correctly and reasonably efficiently when the files are quite different.