An error in % (String Formatting Operator)

[BigShuang]

File location: python-reference/source/docs/str/formatting.rst.

In Syntax %[key][flags][width][.precision][length type]conversion type % values,
the conversion type is not optional.
It should be Required, which marks the end of the specifier.

I think only the fields in square brackets are optional.

Corresponding docs: https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting