join (textutils) 2.0.21 MANPAGE doesn't mention sorting input files

But info page does. Really a bother.

tia,
Bruce


shell:
    $ join --version
    join (textutils) 2.0.21
    Written by Mike Haertel.
    $

manpage:
    ...
    DESCRIPTION
           For  each  pair of input lines with identical join fields, write a line
           to standard output.  The default join field is the first, delimited  by
           whitespace.   When FILE1 or FILE2 (not both) is -, read standard input.
    ...
    
info file (coreutils) Top:
    GNU Core-utils
**************    
    
    This manual documents version 4.1.9 of the GNU command line utilities.
    ...

info file (coreutils) join invocation:
    ...
       Either FILE1 or FILE2 (but not both) can be `-', meaning standard
    input.  FILE1 and FILE2 should be sorted on the join fields.
    ...