Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -2699,12 +2699,14 @@
 **
 ** ^The first parameter to the authorizer callback is a copy of the third
 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
 ** the particular action to be authorized. ^The third through sixth parameters
-** to the callback are zero-terminated strings that contain additional
-** details about the action to be authorized.
+** to the callback are either NULL pointers or zero-terminated strings
+** that contain additional details about the action to be authorized.
+** Applications must always be prepared to encounter a NULL pointer in any
+** of the third through the sixth parameters of the authorization callback.
 **
 ** ^If the action code is [SQLITE_READ]
 ** and the callback returns [SQLITE_IGNORE] then the
 ** [prepared statement] statement is constructed to substitute
 ** a NULL value in place of the table column that would have