Wikipedia
Tri-Ess (Society for the Second Self) is an international educational, social, and support group for heterosexual cross-dressers, their partners, and their families.
Tri-Ess has more than 30 chapters nationwide in the United States, and is a member of the World Congress of Transgender Organizations.
The Tri-Ess vision statement is expressed in the acronym FIBER:
Full personality expression, in a blending of both our masculine and feminine characteristics, in order to be all we can be.
Integration of our masculinity and femininity to create a happier, more complete, person as we use our enhanced understanding of ourselves in our daily lives.
Balance between masculinity and femininity in our total personalities.
Education of Crossdressers toward self-acceptance, education of our families toward understanding, and education of society toward the acceptance of Crossdressers as ordinary people with a special gender gift.
Relationship-building in the context of crossdressing.