Ballroom dance has always been fluid, with new dances or folk dances being added to or removed from the ballroom repertoire from time to time, so no list of subcategories or dances is any more than a description of current practices. There are other dances historically accepted as ballroom dances, and are revived via the vintage dance movement. In Europe, Latin Swing dances include Argentine tango, mambo, Lindy Hop, swing boogie (sometimes also known as nostalgic boogie), and disco fox. One example of this is the subcategory of cajun dances that originated in Acadiana, with branches reaching both coasts of the United
Ballroom dance Smooth and American Rhythm) also exists. The dance technique used for both International and American styles is similar, but International Ballroom allows only closed dance positions, whereas American Smooth allows closed, open and separated dance movements. In addition, different sets of dance figures are usually taught for the two styles. International Latin and American Rhythm have different styling, and have different dance figures in their respective syllabi. Other dances sometimes placed under the umbrella "ballroom dance" include nightclub dances such as Lindy Hop, West Coast swing, nightclub two step, hustle, salsa, and merengue. The categorization of dances as "ballroom dances"