We examined understanding of the title "Ms.", in college students and individuals surveyed via the Internet. Participants were asked to define Ms. and other titles, and rate the likely marital status and age of those using the titles. While some participants indicated that Ms. was a title for women of any marital status, a common alternative definition of Ms. was a title for unmarried women. Younger participants (those under 20) were significantly more likely to use this definition. We also asked what title women preferred for themselves. Older unmarried women were more likely to prefer Ms. as their own title than were younger unmarried women, while married women overwhelmingly preferred the use of "Mrs." Perhaps this is why many younger people assume that Ms. is a title for unmarried women too old to use "Miss". (Contains 3 tables.)