Some people write in their Curriculum Vitae that they have a stutter. Chances are that they receive less answers or interviews, but at least the company knows already, and if you still get a call, that means that they will not just go and make you waste your time, and you have an actual chance of getting the job. Also depending on the work field and/or the country, some companies are encouraged to include people with disabilities and they actually want to be able to show that they have a diverse group of workers.