File contents (noted below as file transmission) can be sent in one of two forms. The simpler form is a number of bytes, followed by a linefeed, followed by the specified number of bytes of file contents. These are the entire contents of the specified file.

In no case are the file contents followed by any additional data. The transmission of a file will end with a linefeed iff that file (or its compressed form) ends with a linefeed.

The encoding of file contents depends on the value for the -k option. If the file is binary (as specified by the -kb option in the appropriate place), then it is just a certain number of octets, and the protocol contributes nothing towards determining the encoding (using the file name is one widespread, if not universally popular, mechanism). If the file is text (not binary), then the file is sent as a series of lines, separated by linefeeds. If the keyword expansion is set to something other than -ko, then it is expected that the file conform to the RCS expectations regarding keyword expansion--in particular, that it is in a character set such as ASCII in which 0x24 is a dollar sign ($). If the file is an encoded file (-ku, or -k{...}) then the file transmission is as above but the encoding is always UTF-8. It is the responsibility of the client to expand the file to an encoding compatible with the client platform.