What does S/TE mean?

[Sik]

If you look at the official docs, the shadow/highlight enable bit is called S/TE. Now, E is a common suffix in register bits (it means "enable"), so that means the official name for the mode is S/T. While S is easy to guess ("shadow"), what the heck does T stand for?

I know we don't have any official information on this but I want to know if anybody can try to guess it (・～・) I'm assuming it's some waseigo-induced name (in waseigo it's very common for loaned words to be used for a completely different meaning, e.g. "tension" to mean "excitement"), since the unabbreviated text does indeed refer to shadow and highlight. Any ideas?

For the record, they couldn't agree on the spelling of highlight it seems. In the register list it says HILIGHT, while in the S/H section it says HIGHRIGHT (was this even translated by SOA?).

[Flygon]

I'm going to take a - probably pretty bad - stab at assuming it may mean Transparency or Translucency.

[Sik]

...I suddenly feel kind of dumb for not thinking on that one (especially since its main use was indeed to make translucent graphics to do shadows).