This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

None

None
is a setting used for certain options.
For ContourPlot, use None to only show the contour lines:
Plot only mesh lines:
Use None to indicate holes or no content for mesh regions:
Use None to indicate no vertex labels should be used:
For ContourPlot, use None to only show the contour lines:
In[1]:=
Click for copyable input
Out[1]=
 
Plot only mesh lines:
In[1]:=
Click for copyable input
Out[1]=
 
Use None to indicate holes or no content for mesh regions:
In[1]:=
Click for copyable input
Out[1]=
 
Use None to indicate no vertex labels should be used:
In[1]:=
Click for copyable input
Out[1]//TreeForm=
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