+** SQL function is used. A function implementation with a non-negative
+** nArg parameter is a better match than a function implementation with
+** a negative nArg. A function where the preferred text encoding
+** matches the database encoding is a better
+** match than a function where the encoding is different.
+** A function where the encoding difference is between UTF16le and UTF16be
+** is a closer match than a function where the encoding difference is
+** between UTF8 and UTF16.
+**
+** Built-in functions may be overloaded by new application-defined functions.
+** The first application-defined function with a given name overrides all
+** built-in functions in the same [database connection] with the same name.
+** Subsequent application-defined functions of the same name only override
+** prior application-defined functions that are an exact match for the
+** number of parameters and preferred encoding.
+**
+** An application-defined function is permitted to call other
+** SQLite interfaces. However, such calls must not
+** close the database connection nor finalize or reset the prepared
+** statement in which the function is running.