The corresponding VECT object is written to standard output. If no non-blank text characters are given, hvectext produces a null geom object ("{ }") as output.
The special option -- marks the end of options; it's useful in case the text itself begins with a hyphen.
Hvectext accepts Ghostscript Hershey fonts; the built-in default is Hershey-Plain-Simplex a.k.a. hrpl_s.gsf. Others of interest: hrsy_r.gsf (Symbol), hrpl_t.gsf (Triplex). For a complete list, see all the Ghostscript font files of nontrivial size whose names begin with "hr".
Although there's no way to switch fonts within the string, the first line of output from hvectext is an OOGL comment resembling:
# Continue with: -align sw -plane xy -s 0.25 -at 1.24378 0 0giving options for hvectext to continue the string where it left off.
/usr/local/lib/ghostscript/fonts is searched if -hershey is given and GS_FONTPATH isn't set.