K 10 svn:author V 6 kevans K 8 svn:date V 27 2018-08-20T00:51:19.882026Z K 7 svn:log V 486 MFC r337666: getopt_long(3): Document behavior, optstring leading characters Leading '+', '-', and ':' in optstring have special meaning. We briefly mention that the first two have special meaning in that we say POSIXLY_CORRECT turns them off, but we don't actually document their meaning. Add a paragraph to RETURN VALUES explaining how they control the treatment of non-option arguments. A leading ':' has no mention; add a note that it suppresses warnings about missing arguments. END