[Corpora-List] About multiple sense tags used in the answer key file of Senseval

[Yuanyong Wang]

         Dear list memebers, I'm a research student doing research on NLP,
word sense disambiguation in particular. I am planning to conduct
experiment on the Senseval-3 data. But after reading the answer key file,
one fact appears a bit confusing, sometimes for one test case, multiple sense
tags are given, and one of the multiple sense tags could be simply a
letter "U". I tried and looked into the documentation, but haven't found
any relevant information.  Could anyone kindly tell me how to make sense
of those multiple sense tag cases or probably point me to the relevant
documentation?


       Regards
       Robin.