Issue #21240: Add an abstractmethod directive to mark abstract methods in the docs more explicitly
diff --git a/Doc/library/numbers.rst b/Doc/library/numbers.rst
index 8ab07d0..718a50e 100644
--- a/Doc/library/numbers.rst
+++ b/Doc/library/numbers.rst
@@ -35,7 +35,7 @@
 
       Abstract. Retrieves the imaginary component of this number.
 
-   .. method:: conjugate()
+   .. abstractmethod:: conjugate()
 
       Abstract. Returns the complex conjugate. For example, ``(1+3j).conjugate()
       == (1-3j)``.