Highlight information about avoiding labels in legend

Author: oscargus

lib/matplotlib/axes/_axes.py

@@ -215,11 +215,13 @@ def legend(self, *args, **kwargs):
             line.set_label('Label via method')
             ax.legend()
 
-        Specific lines can be excluded from the automatic legend element
-        selection by defining a label starting with an underscore.
-        This is default for all artists, so calling `.Axes.legend` without
-        any arguments and without setting the labels manually will result in
-        no legend being drawn.
+        .. note::
+            Specific artists can be excluded from the automatic legend element
+            selection by using a label starting with an underscore, "_".
+            A string starting with an underscore is the default label for all
+            artists, so calling `.Axes.legend` without any arguments and
+            without setting the labels manually will result in no legend being
+            drawn.
 
 
         **2. Explicitly listing the artists and labels in the legend**

tutorials/intermediate/legend_guide.py

@@ -47,8 +47,9 @@
 not all artists can be added to a legend, at which point a "proxy" will have
 to be created (see :ref:`proxy_legend_handles` for further details).
 
-Those artists with an empty string as label or with a label starting with
-"_" will be ignored.
+.. note::
+    Artists with an empty string as label or with a label starting with an
+    underscore, "_", will be ignored.
 
 For full control of what is being added to the legend, it is common to pass
 the appropriate handles directly to :func:`legend`::