B106 and P103
http://forums.sjgames.com/showpost.php?p=722520&postcount=2 has Kromm mention All-Out Attack Jet "AOA (Jet)" for flamethrowers in High Tech and in this 2009 post also states
- a 10-yard melee weapon that cannot parry or be parried, and that inflicts only half damage past five yards
It is unclear if this was mentioned anywhere prior.
Melee-Capable can add parrying.
GURPS Magic 73 has Flame Jet Spell say "This attack may be dodged or blocked, but not parried"