handling c/o in string? Error.

[syurdin]

probablepeople.RepeatedLabelError: ERROR: Unable to tag this string because more than one area of the string has the same label

ORIGINAL STRING: c/o Denise M. Block PARSED TOKENS: [(u'c/o', 'Surname'), (u'Denise', 'GivenName'), (u'M.', 'MiddleInitial'), (u'Block', 'Surname')] UNCERTAIN LABEL: Surname