minor: docs

Author: Mike Dirolf

pymongo/collection.py

@@ -209,12 +209,14 @@ def update(self, spec, document,
  :Parameters:
  - `spec`: a SON object specifying elements which must be present for
  a document to be updated
- - `document`: a SON object specifying the fields to be changed in the
- selected document, or (in the case of an upsert) the document to
- be inserted
+ - `document`: a SON object specifying the document to be used for the
+ update or (in the case of an upsert) insert. For more information
+ on update syntax / modifiers see the MongoDB wiki_.
  - `upsert` (optional): perform an upsert operation
  - `manipulate` (optional): manipulate the document before updating?
  - `safe` (optional): check that the update succeeded?
+
+ .. _wiki: http://www.mongodb.org/display/DOCS/Updating
  """
  if not isinstance(spec, types.DictType):
  raise TypeError("spec must be an instance of dict")