- The BEGIN and END arguments are characters. (Currently, BEGIN can be any
- token type, but you probably shouldn't rely on this.)"
+ The BEGIN and END arguments are the start and end delimiters. BEGIN can
+ be any token type, but is usually a delimiter character; it may also be t
+ to mean `don't care' -- but there must be an initial token of some kind
+ for annoying technical reasons. END may be either a character or a list
+ of characters. If KEEP-END is true, the trailing delimiter is left in the
+ token scanner so that it's available for further parsing decisions: this
+ is probably what you want if END is a list."