Problema with lowercase_keyword

I'm using elastic 1.5.1 but when i try to input one document i got this error:

Caused by: org.elasticsearch.index.mapper.MapperParsingException: Wrong value for index [lowercase_keyword] for field [logradouro]

so i have numbers, - , /, spaces, ' , ", ~, º and others in this field, how chars I cant use in this field??

tks