Description of SIGHUP GUC parameters

Currently, the standard boilerplate description of a SIGHUP parameter
is

        This option can only be set at server start or in the
        <filename>postgresql.conf</filename> file.

We've heard from more than one person who found this confusing ---
frequently it's misread as saying that the parameter cannot be changed
after postmaster start.  Doubtless this is partly because the
boilerplate phrase for a POSTMASTER parameter is

        This option can only be set at server start.

However, previous discussions have dried up without coming up with a
better phrase.  It occurred to me today that this might work better:

        This option can only be set in the <filename>postgresql.conf</>
        file or on the server command line.

I think mentioning the config file first is important to focus attention
on that.  The only other way to set these parameters is via command-line
switches, so we should just say that rather than emphasizing the "server
start time" aspect of it, which is exactly what not to emphasize.

Comments?

            regards, tom lane