Issue #15096: Drop support for the ur string prefix
diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst
index c94a47f..5e5903f 100644
--- a/Doc/reference/lexical_analysis.rst
+++ b/Doc/reference/lexical_analysis.rst
@@ -401,7 +401,7 @@
.. productionlist::
stringliteral: [`stringprefix`](`shortstring` | `longstring`)
- stringprefix: "r" | "u" | "ur" | "R" | "U" | "UR" | "Ur" | "uR"
+ stringprefix: "r" | "u" | "R" | "U"
shortstring: "'" `shortstringitem`* "'" | '"' `shortstringitem`* '"'
longstring: "'''" `longstringitem`* "'''" | '"""' `longstringitem`* '"""'
shortstringitem: `shortstringchar` | `stringescapeseq`
@@ -444,19 +444,21 @@
As of Python 3.3 it is possible again to prefix unicode strings with a
``u`` prefix to simplify maintenance of dual 2.x and 3.x codebases.
-Both string and bytes literals may optionally be prefixed with a letter ``'r'``
+Bytes literals may optionally be prefixed with a letter ``'r'``
or ``'R'``; such strings are called :dfn:`raw strings` and treat backslashes as
literal characters. As a result, in string literals, ``'\U'`` and ``'\u'``
-escapes in raw strings are not treated specially.
+escapes in raw strings are not treated specially. Given that Python 2.x's raw
+unicode literals behave differently than Python 3.x's the ``'ur'`` syntax
+is not supported.
.. versionadded:: 3.3
The ``'rb'`` prefix of raw bytes literals has been added as a synonym
of ``'br'``.
.. versionadded:: 3.3
- Support for the unicode legacy literal (``u'value'``) and other
- versions were reintroduced to simplify the maintenance of dual
- Python 2.x and 3.x codebases. See :pep:`414` for more information.
+ Support for the unicode legacy literal (``u'value'``) was reintroduced
+ to simplify the maintenance of dual Python 2.x and 3.x codebases.
+ See :pep:`414` for more information.
In triple-quoted strings, unescaped newlines and quotes are allowed (and are
retained), except that three unescaped quotes in a row terminate the string. (A