Indeed, on OS/2 one didn't google for the error code. One used the HELP command, one of whose modes of operation was looking up and printing the short and long message texts for such codes. The latter would often contain both EXPLANATION and ACTION parts.

    [C:\]help sys0003 
    SYS0003: The system cannot find the path specified. 
    EXPLANATION: The path named in the command does not 
    exist for the drive specified or the path was 
    entered incorrectly. 

    [C:\]help sys0002
    SYS0002: The system cannot find the file specified.
    Explanation: The filename is incorrect or does not exist. 
    Action: Check the filename and retry the command.