RAdd(args:RichText...):RichText
Concatenate all arguments, which can be strings or rich text, to a new rich text string, and returns that.
If any argument is EMPTY, returns EMPTY. If no arguments are given, returns an empty (=zero length) rich text string.
In text mode, this function produces plain strings instead, as rich text attributes have no meaning to the text mode applications.
Since: PCC2 1.99.21
