Issue #19795: Mark up None as literal text.
diff --git a/Doc/library/xml.sax.reader.rst b/Doc/library/xml.sax.reader.rst
index 14af050..17aa8f0 100644
--- a/Doc/library/xml.sax.reader.rst
+++ b/Doc/library/xml.sax.reader.rst
@@ -306,7 +306,7 @@
    Get the byte stream for this input source.
 
    The getEncoding method will return the character encoding for this byte stream,
-   or None if unknown.
+   or ``None`` if unknown.
 
 
 .. method:: InputSource.setCharacterStream(charfile)