The BDSM Pride Flag is a symbol for the BDSM community which is a marriage between the "Leather Pride Flag" by artist Tony DeBlase and the "BDSM Symbol" by Quagmyr. This flag encompasses those who are into BDSM, leather, Levi's, sado-masochism, bondage and domination, uniform, cowboys, rubber, and other fetishes. The rainbow heart shows the bond between the gay and straight bdsm community. The logo at the heart's core, has a wide range of meanings, and it's placement, on the flag, is significant of the unity between all sexualities.
The three divisions represent the varying threesomes of BDSM. First of all, the three divisions of BDSM itself: B&D, D&S, and S&M. Next, the BDSM creed of behavior: Safe, Sane, and Consensual. Third, the divisions of our community: Tops, Bottoms, and Switches.

For more information on the BDSM logo, check out this webpage by the designer: