docs/builtins: str: Mention that strings are stored with utf-8 encoding.
@@ -193,6 +193,10 @@ Functions and types
.. class:: str()
+ In MicroPython, strings are backed by Unicode UTF-8 encoding. While this
+ fact doesn't have to be known by normal users, advanced users may use it
+ to optimize applications/libraries.
+
.. function:: sum()
.. function:: super()
