Originally Posted by kcjc

11-30 is a Dura-Ace 9100 11-speed setup, https://bike.shimano.com/en-EU/produ.../CS-R9100.html. 11-28/11-32 was/still a common setup for Ultegra 11-speed. Current 12-speed offering is 11-30 &11-34, https://bike.shimano.com/en-EU/produ...-R9200-12.html & https://bike.shimano.com/en-EU/produ...-R8101-12.html.

11-30 as an MTB range dates back to the 8-speed starting from the early 90s.