document labeling autoregressive decoder

neuralmonkey/decoders/sequence_labeler.py

@@ -11,7 +11,18 @@
 
 
 class SequenceLabeler(ModelPart):
-    """Classifier assing a label to each encoder's state."""
+    """Classifier assigning a label to each input state.
+
+    If the labeler output has an input sequence with embeddings, these are used
+    as additional input to the labeler.
+
+    Note that when the labeler is stacked on an autoregressive decoder, it
+    labels the symbol that is currently generated by the decoder, i.e., the
+    decoder's state has not yet been updated by putting the decoded symbol on
+    its input. The label is thus the label of a symbol is generated, not the
+    one has been already generated and put on decoders input as in case of
+    standard sequence labeling.
+    """
 
     # pylint: disable=too-many-arguments
     def __init__(self,