updated docs

docs/docs/ml.xml

@@ -1466,11 +1466,12 @@ Davis E. King. <a href="http://jmlr.csail.mit.edu/papers/volume10/king09a/king09
                 contiguous words which refer to proper names.
 
                <p>
-                The sequence_segmenter is implemented using the BIO (Begin, Inside,
-                Outside) sequence tagging model.  Moreover, the sequence tagging is done
-                internally using a <a href="#sequence_labeler">sequence_labeler</a> object 
-                and therefore sequence_segmenter objects are examples of chain structured
-                conditional random field style sequence taggers. 
+                Internally, the sequence_segmenter uses the BIO (Begin, Inside, Outside) or
+                BILOU (Begin, Inside, Last, Outside, Unit) sequence tagging model.
+                Moreover, it is implemented using a <a href="#sequence_labeler">sequence_labeler</a>
+                object and therefore sequence_segmenter objects are examples of
+                chain structured conditional random field style sequence
+                taggers. 
                </p>
          </description>
       </component>