Note re case-insensitivity

preserves.md

@@ -1403,4 +1403,9 @@ tell whether it is an open-parenthesis or not! For this reason, I've
 disallowed whitespace between a label `Value` and the open-parenthesis
 of the fields. Is this reasonable??
 
+Q. To remain compatible with JSON, portions of the text syntax have to
+remain case-insensitive (`%i"..."`). However, non-JSON extensions do
+not. There's only one (?) at the moment, the `%i"f"` in `Float`;
+should it be changed to case-sensitive?
+
 ## Notes