Rummaging through the forum I found a reference Andrey made to a special character mode behind ctrl+k

I was looking because I wanted to define a unit of $. But the keystroke $ placed an empty variable token, an empty operator token and an empty variable token in with worksheet and while the CurrencyUnits plugin from Davide provided a USD unit I wasn't quite ready to give up on getting the $ symbol for the unit.

What I found was this keystroke sequence defined the $ unit ' ctrl+k $ ctrl+k : ' ctrl+k $ ctrl+k and what appeared in my worksheet was just what I wanted.

Thank you!

Actually, there is no need to explicitly write such a definition in your sheet unless you want
- to make it appear in the dynamic assistant (perhaps with a description)
- automatic replacement to be performed, e.g. by €.