Fix some markup and one typo
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index bf0899d..09f97a9 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -153,7 +153,7 @@
      conflicting optionals.
 
    * prog_ - The name of the program (default:
-     :data:`sys.argv[0]`)
+     ``sys.argv[0]``)
 
    * usage_ - The string describing the program usage (default: generated)