[tex-k] METAFONTk and MetaPostk, and -parse-first-line

[Karl Berry]

    This last exchange prompts me to ask the question: 
    where is this feature documented, 

I wrote the initial description in the Web2c Texinfo manual.  I can't
find a url for the current version in HTML offhand, but there's an older
version at http://www.tug.org/web2c/manual, and a pdf of the current
version at
http://tug.org/ftp/texlive/Contents/live/texmf/doc/web2c/web2c.pdf.
Maybe someday I or Olaf or someone will get everything to date.

    and  where is the entry in the texmf.cnf file documented, (if any ?) 

I do not see either the texmf.cnf entry or the command line option in
the current documentation :(.