Decode chinese spark plug
 

http://www.torchgroup.cn/upload/2010712325416241.jpg
http://www.torchgroup.cn/upload/2010712325567725.jpg
Heat rating: Similar to NGK
R Resistor type NGK= R
T Projected (凸 Tū) center electrode insulator NGK= P
C Copper core center electrode NGK= S

Excellent info. Thanks!

X2; thank you Humanbeing. :)

Newest industry standard is QC/T 430-2014 [Road vehicles Editorial nominating method for the type designation of spark-plugs / Release date:Oct 14 2014 / Effective date:Apr 01 2015]
the Draft for Approval pdf: https://drive.google.com/file/d/0B2b...ew?usp=sharing

Examples of those "unusual" spark plug.
J Triple ground
http://img.alicdn.com/imgextra/i1/19...1916379083.jpg
PP Double platinum
http://gd2.alicdn.com/imgextra/i2/19...1970487023.jpg
I iridium U "U" groove
http://img.alicdn.com/imgextra/i1/17...1705976459.jpg