Mention backports (GH-18715)

diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst
index 9e317816abb505ec97ab731ed7c271456c13e467..69a20fca17898abbc6f7a81dfc7ba5ab85cbb2c1 100644 (file)
--- a/Doc/library/decimal.rst
+++ b/Doc/library/decimal.rst
@@ -1485,7 +1485,7 @@ are also included in the pure Python version for compatibility.
    the C version uses a thread-local rather than a coroutine-local context and the value
    is ``False``.  This is slightly faster in some nested context scenarios.
 
-.. versionadded:: 3.9
+.. versionadded:: 3.9 backported to 3.7 and 3.8.
 
 
 Rounding modes