diff --git a/doc/source/user_guide/reshaping.rst b/doc/source/user_guide/reshaping.rst
index 7e890962d8da1..c476e33b8ddde 100644
--- a/doc/source/user_guide/reshaping.rst
+++ b/doc/source/user_guide/reshaping.rst
@@ -471,9 +471,8 @@ If ``crosstab`` receives only two Series, it will provide a frequency table.
 
     pd.crosstab(df['A'], df['B'])
 
-Any input passed containing ``Categorical`` data will have **all** of its
-categories included in the cross-tabulation, even if the actual data does
-not contain any instances of a particular category.
+``crosstab`` can also be implemented
+to ``Categorical`` data.
 
 .. ipython:: python
 
@@ -481,6 +480,15 @@ not contain any instances of a particular category.
     bar = pd.Categorical(['d', 'e'], categories=['d', 'e', 'f'])
     pd.crosstab(foo, bar)
 
+If you want to include **all** of data categories even if the actual data does
+not contain any instances of a particular category, you should set ``dropna=False``.
+
+For example:
+
+.. ipython:: python
+
+    pd.crosstab(foo, bar, dropna=False)
+
 Normalization
 ~~~~~~~~~~~~~