European Patent: 0 541 796 B1
International Patent: PCT / JP 90 / 00651 PCT / 1768023 PCT / 2001 – 165956
International Homologation: W0 91 / 17957 28.11.91 G.91 / 27
Index C15: C 01 G 49 / 00
Trademark: Nr. 39906218.1
Name: PI, π, registered trademark Nr.: 399 06 220.3 and Nr.: 399 06 217.3