Abbreviations in full text search index
When you want to add words involving special characters that you want treated as a single word, you will want to create a custom dictionary. 

Creating Custom Dictionaries for special terms to be indexed ‘as-is’ in SQL Server 2008 Full-Text Indexes

Be aware that custom dictionaries are limited in size, plus the larger the dictionary the slower fulltext can become.

Custom dictionaries are great when you have a limited set of words to add like AT&amp;T or M&amp;Ms which are words with special characters that might be used over and over that you wanted treated as a single word instead of the default word breaking behavior.

Custom dictionaries are not great for for words like part numbers (ex. JY-14562, PTW-14432, etc.) where every row in a table would result in a new entry in the custom dictionary. You could potentially have several hundred thousand or more unique part numbers. That would not be a good use for custom dictionary.  If you need this type of behavior, you are better off writing your own word breaker. Creating word breakers is not well documented nor easy to create, but it does allow you to decide how you want words broken when you encounter special characters.