The octagonal trigram template is a common symbol for the term Bagua.
The template has eight (ba) areas (guas), connecting two neighbouring corners of the octagonal
trigram towards the centre to form one gua.
The centre contains the yin and yang symbol, or taijitu as per taoist philosophy.
Each of the ‘guas’ shows three yao symbols, stretching in three rows from the centre to the outer
side.
Each single yao symbol (line symbol) is either yin (representing the receptive, female force of
nature), or yang (representing the creative, male force of nature).
For more information, visit: http://www.nationsonline.org/oneworld/Chinese_Customs/bagua.htm