The Symbol of Scientology consists of the letter “S” interlaced with two triangles. According to Church of Scientology literature, each triangle represents three inseparably linked concepts.
The triangles are the “KRC” triangle, (Knowledge, Responsibility and Control) and the “ARC” (Affinity, Reality and Communication) triangles, representing concepts intrinsic to the dogma of Scientology.
The S, of course, stands for “Scientology.”
See also: Scientology at Alternative Religions