In the SCA, a Don, or the feminine equivalent Doña (sometimes Dona) is often a member of the Order of the White Scarf, or other high fencing award. However, it is technically a Spanish alternate title either for those who have received an AoA, used in place of Lord , or for a knight, instead of Sir. Generally speaking, in places with a strong fencing tradition, the use of "Don" or "Doña" by those who have not received the appropriate award is considered pretty tacky. This may be restricted to the fencing community or to the Kingdom at large, depending on how well integrated the fencing community is with the Kingdom. In most White Scarf Kingdoms, for instance, it's pretty universal for the honorific to be used only by the holders of the fencing award. Use of the title by knights is uncommon, most knights tend to prefer "Sir" regardless of persona.