The Cats on Stamps Study Unit is a nonprofit organization (ISN 0891-8635) of the American Topical Association (ATA), affiliated with the American Philatelic Society (APS). Membership dues are $14/year U.S.; $20/year all others,  or $10 for only the PDF version. Two-year renewals: $25 U.S.; $35 all others. Membership in ATA is not required.

A Brief History

   In the fall of 1979, Virginia Haywood, an enthusiastic stamp collector published the first issue of Cat Mews, continuing the newsletter through 1981.
   Robert F. Yost revived the publication in 1985 through 1989. His efforts led to the American Topical Association Charter of the Cats on Stamps Study Unit (COSSU) on May 22, 1985 and in 1989, COSSU was also approved by the American Philatelic Society (APS) as an affiliate. 
   The group was reactivated in 1994 thanks to Donna Wilson, Virginia Gifford, Susan Minniear, and others. Cat Mews resumed publication with Virginia Gifford as editor.
   Virginia's untimely death in the summer of 1994 brought Frank and Nancy Ladd to the helm. Cat Mews earned the first of many APS literary competition awards. Frank remained the editor until the close of 1999.
  Beginning with the first issue of 2000, Marci Jarvis assumed the editorial duties for Cat Mews. The journal garnered more APS literary awards. Two full color pages  were introduced in 2004, a yearly index in 2007, and four additional pages were added in 2009. In 2011, Cat Mews changed to a magazine-style format.
  COSSU has members from more than a dozen countries.