Clarify implications of non-empty LAYOUT
@@ -506,9 +506,11 @@ comments like the one used in the grammar language itself:
NotComment: /((\*[^\/])|[^\s*\/]|\/[^\*])+/;
!!! note
- If `LAYOUT` is provided it *must* match between any two tokens including the
- beginning and end of the input. If layout is optional be sure to include
- `EMPTY` as one of its alternatives like in the previous examples.
+ If `LAYOUT` is provided it *must* match before the first token, between any
+ two tokens in the input, and after the last token. If layout cannot be
+ empty, the input cannot start or end with a token. If this is not desired,
+ make sure to include `EMPTY` in the layout as one of its alternatives like
+ in the previous examples.
## Handling keywords in your language
