A full-text index stores number words twice, once as they appear in the text and secondly prefixed with "nn", for example, the number 14 will get stored as "14" and "nn14". I'm not totally sure of the reason for this?!
This is problematic when trying to return genuine "nn14" strings as results include all records containing just the number 14 as well as the "nn14" string. The data set I have indexed is UK address data so searching for the string "NN14" should ideally return just address with the postcode NN14, but I also get thousands of records just with the number 14 in them.
Is there any way to avoid this behaviour? Ideally I'd like to have some control over the word breaker that builds the index so it doesn't save the "nn" prefix version.