whatsnew

Author: rhshadrach

doc/source/whatsnew/v3.0.0.rst

@@ -117,6 +117,9 @@ process in more detail.
 
     `PDEP-7: Consistent copy/view semantics in pandas with Copy-on-Write <https://pandas.pydata.org/pdeps/0007-copy-on-write.html>`__
 
+Setting the option ``mode.copy_on_write`` no longer has any impact. The option is deprecated
+and will be removed in pandas 4.0.
+
 .. _whatsnew_300.enhancements.col:
 
 ``pd.col`` syntax can now be used in :meth:`DataFrame.assign` and :meth:`DataFrame.loc`