Visible is introduced as a -20% limitation for Telekinesis on B92
GURPS Power-Ups 8 pg 14 broadened this for a bigger variety of abilities, being -10% for communication ones and -20% for attack ones like TK
Examples[]
GURPS Sorcery: Protection and Warning Spells
- pg 6 for Force Dome and pg 14 for Utter Dome apply the -10% version to Damage Resistance (this 2016 publication by PK contradicts his earlier work in Monster Hunters 1 which appends No Signature to DR) in line with pg 4's armor afflicting DR as "an invisible field of pure force" without No Sig
quotes[]
http://forums.sjgames.com/showpost.php?p=778887&postcount=7
adding Ranged does turn it into a Healing Ray. This makes sense, since it's not a contested thing, and healing rays have a fair amount of fictional precedent.
That said, it wouldn't be visible unless you added Visible