What can or can't I enter in a field type RCHAR?

Thanks

Generally these are key fields, so A-Z, 0-9, sometimes a-z depending on profile options and generally no special characters (which are discouraged in any case). The characters are right justified and leading Eros are removed.

Andrew - I don't think any fields allow the Greek god of love.

MikeS - " ... leading zeros are removed."

Bloody mobile keyboards. Z is next to shift-up! Doesn't usually result in such a good typo.

I thought that was on purpose, since it removed the leading character of the word zero.