RS                           Record Separator

    Input record separator.  Default  value == "\n".  The  record separator
    may  have  any  value:    regular  expression, string or numeric.  When
    assigned a value it is converted to  a string value.  If the length  of
    the string is a single character, that character is used as the  single
    character record separator.   However, if  the length of  the resulting
    string  is  longer  than  one  character,  it  is  treated as a regular
    expression and converted  to internal form  at the time  of assignment.
    The  regular  expression  is  then  used  to  scan the input file for a
    matching string.  The matching string is used as the record separator.

    This behavior is consistent with the use of the FS variable.