BACK_QUOTE

A back-quote (`) precedes a metacharacter to cause it to be treated as an ordinary character. Since no metacharacters are alphanumeric, and since non-alphanumeric characters are always tokenized individually, back-quote only operates on the single character following it. Note that since back-quote is itself a metacharacter, two successive backquotes indicates a single back-quote should be parsed from the Avail source code.

The only characters that can be backquoted (and must be to use them in a non-special way) are the Metacharacters, space, and the circled numbers.