An abstract shape seen in Asian family crests and corporate logos, and used by groups ranging from Germanic neopagans to Buddhists.
The triple-6 of the Buddhist Tomoe symbol have nothing to do with the Western interpretation of 666. In the Tomoe, they look a bit like three backward commas or teardrops, chasing one another round a circle. The symbol is used during meditation.
In Japan both the Tomoe and the related Triquetra are used as kamon, a sort of heraldic coat of arms (ka means 'family' and mon means 'crest'). Like the cross in European heraldry, kamon were used especially in battle to identify individuals or members of a clan. They were first owned by the aristocracy and later rolled out to anyone associated with that community. Kamon are still used by Japanese, especially as decorations on their formal kimono.
Variants of the symbol are found in Korea (known as sam-taegeuk) and in Tibet (known as Gankyil).
In Northern Europe, the symbol is used by Germanic neopagans, such as the Odinic Rite (in the UK).