Issue 1:
These can be seen by inspecting the __call__ attribute, but they are referenced from the particular plotting methods, but not easily learned about in IPython/Jupyter.

https://github.com/pandas-dev/pandas/blob/master/pandas/tools/plotting.py#L3781

Issue 2:
I'm running into a problem with using dropna with a list of columns specified by subset. I wish to remove rows with missing values:

The dataset looks like this:

However, when I try to call dropna using these columns, it complains about a duplicate axis:

variables.dropna(subset=['cigarette_smokers', 'birth_wt_child',
'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-168-96be0b0b00e8> in <module>()
1 variables.dropna(subset=['cigarette_smokers', 'birth_wt_child',
----> 2 'oxygen', 'length_of_stay', 'hospitalized_vitamin_d', 'breastfed'])

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in dropna(self, axis, how, thresh, subset, inplace)
2407 if subset is not None:
2408 agg_axis_name = self._get_axis_name(agg_axis)
-> 2409 agg_obj = self.reindex(**{agg_axis_name: subset})
2410
2411 count = agg_obj.count(axis=agg_axis)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in reindex(self, index, columns, **kwargs)
2160 def reindex(self, index=None, columns=None, **kwargs):
2161 return super(DataFrame, self).reindex(index=index, columns=columns,
-> 2162 **kwargs)
2163
2164 @Appender(_shared_docs['reindex_axis'] % _shared_doc_kwargs)

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in reindex(self, *args, **kwargs)
1561 return self._reindex_axes(axes, level, limit,
1562 method, fill_value, copy,
-> 1563 takeable=takeable).__finalize__(self)
1564
1565 def _reindex_axes(self, axes, level, limit, method, fill_value, copy,

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_axes(self, axes, level, limit, method, fill_value, copy, takeable)
2110 if columns is not None:
2111 frame = frame._reindex_columns(columns, copy, level, fill_value,
-> 2112 limit, takeable=takeable)
2113
2114 index = axes['index']

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/frame.pyc in _reindex_columns(self, new_columns, copy, level, fill_value, limit, takeable)
2137 return self._reindex_with_indexers({1: [new_columns, indexer]},
2138 copy=copy, fill_value=fill_value,
-> 2139 allow_dups=takeable)
2140
2141 def _reindex_multi(self, axes, copy, fill_value):

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/generic.pyc in _reindex_with_indexers(self, reindexers, method, fill_value, limit, copy, allow_dups)
1687 new_data = new_data.reindex_indexer(index, indexer, axis=baxis,
1688 fill_value=fill_value,
-> 1689 allow_dups=allow_dups)
1690
1691 elif (baxis == 0 and index is not None and

/Library/Python/2.7/site-packages/pandas-0.13.0_395_gef55e60-py2.7-macosx-10.9-intel.egg/pandas/core/internals.pyc in reindex_indexer(self, new_axis, indexer, axis, fill_value, allow_dups)
3227 # trying to reindex on an axis with duplicates
3228 if not allow_dups and not self.axes[axis].is_unique:
-> 3229 raise ValueError("cannot reindex from a duplicate axis")
3230
3231 if not self.is_consolidated():

ValueError: cannot reindex from a duplicate axis

Running a current build from master in Python 2.7.5 on OS X 10.9.1.