*** There are two new syntax-codes, `!' and `|' (numeric values 14
and 15). A character with a code `!' starts a comment which is ended
only by another character with the same code (unless quoted). A
character with a code `|' starts a string which is ended only by
another character with the same code (unless quoted).
These codes are mainly meant for use as values of the `syntax-table' text property.