Scouting memorabilia collecting is the hobby and study of preserving and cataloging Boy Scouting and Girl Guiding items for their historic, aesthetic and monetary value. Since collecting depends on the interests of the individual collector, the depth and breadth of each collection varies. Some collectors choose to focus on a specific subtopic within their area of general interest, for example insignia issued prior to the 1970s Boy Scouts of America requirement that all insignia have either the fleur-de-lis or the acronym BSA; or only the highest ranks issued by each nation. Others prefer to keep a more general collection, accumulating any or all Scouting merchandise, or Scouting stamps from around the world.