Explain better this new inventory for Word Sense Disambiguation
The paper says:


  "we also added the semantically-empty label named GENERAL to our inventory to cover the 135 categories that could not be included in any cluster."


I suggest you read that as though it had said


  we also added the label named GENERAL to our inventory to cover the 135 categories that could not be included in any cluster.  This label is not associated with one specific semantic meaning; it is a catch-all for the categories that could not be mapped to any of the other labels.