To check-in our file to RCS, you would issue the command:

$ ci our_file.txt

RCS will respond with:

RCS/our_file.txt,v  <--  our_file.txt
enter description, terminated with single '.' or end of file:
NOTE: This is NOT the log message!
>> 

RCS displays the locations of the working file and the RCS file, and the prompts for a description. The default check-in behavior deletes the working file from the current directory if it is successfully checked-in. In this example, the location of the RCS file is in the RCS subdirectory with the name of the working file with a comma and the lowercase letter v (,v) appended to the filename. A ,v is the default extension to RCS files. There are few reasons to change this behavior, but this behavior can be modified so RCS looks for a different extension for RCS files (see section on extension option). If the current directory does not have an RCS subdirectory, then the RCS file is placed in the same directory as the working file.

After displaying the files in consideration, RCS gives directions on how to submit a file description (see section on file description). After these directions an interactive prompt expects a description to be inputed.