doc: minimal provenance documentation

Author: satra

doc/devel/index.rst

@@ -17,6 +17,7 @@ conventions documented in the `NIPY Developers Guide
    writing_custom_interfaces
    gitwash/index   
    architecture
+   provenance
 
 
 .. include:: ../links_names.txt

doc/devel/provenance.rst

@@ -0,0 +1,21 @@
+================
+W3C PROV support
+================
+
+Overview
+--------
+
+We're using the the `W3C PROV data model <http://www.w3.org/TR/prov-dm/`_ to
+capture and represent provenance in Nipype.
+
+For an overview see:
+
+`PROV-DM overview <http://slideviewer.herokuapp.com/url/raw.github.com/ni-/notebooks/master/NIDMIntro.ipynb>`_
+
+Each interface writes out a provenance.json (currently prov-json) or
+provenance.rdf (if rdflib is available) file. The workflow engine can also
+write out a provenance of the workflow if instructed.
+
+This is very much an experimental feature as we continue to refine how exactly
+the provenance should be stored and how such information can be used for
+reporting or reconstituting workflows.