Notes:
However the next example for a meta-language token, maybe written by another programmer - is even more aggressive: here the programmer uses underlining as the quoting mechanism to denote the internal token value. So we have the use of formatting for delimiting - a concept that is not in any computer language today - even though it is very common in our informal communications, for example the use of indentation for grouping ideas or the use of fraction lines to define the operands of a division.