In base 27, triplets of ternary digits are encoded in heptavintimal digits. There is a need for an encoding akin to hexdecimal for ternary computers. Heptavintimal meets this need, offering a natural encoding for 3-trit trybbles.
http://wiki.xxiivv.com/site/heptavintimal
@neauoire
Interesting… an heptavintimal digit can be expressed using the 26 letters of the ASCII alphabet plus the 0.