Up through version 2016f, the specification was...
# For companies who don't want to put time zone specification in
# their installation procedures.  When users run date, they'll get the message.
# Also useful for the "comp.sources" version.

# Zone  NAME    GMTOFF  RULES   FORMAT
Zone    Factory 0       - "Local time zone must be set--see zic manual page"
...while since 2016g the specification has been...
# For distributors who don't want to put time zone specification in
# their installation procedures.  Users that run 'date' will get the
# time zone abbreviation "-00", indicating that the actual time zone
# is unknown.

# Zone  NAME    GMTOFF  RULES   FORMAT
Zone    Factory 0       -       -00

While the old version may have led to a more instructive result from the first command line invocation of "date," the new version produces  result that is standard conforming.

    @dashdashado

On Thu, Aug 10, 2023 at 3:22 PM Garrett Wollman via tz <tz@iana.org> wrote:
<<On Thu, 10 Aug 2023 12:19:15 -0700, Justin Grant via tz <tz@iana.org> said:

> There's a Zone called "Factory". What is its purpose, and how is it used?

It is intended for use as a factory default, to clearly indicate an
unconfigured system rather than one that is intentionally configured
to run on UTC.

-GAWollman