Originally Posted by
badatz
If only you were correct on this point, but you are not. Manufacturers can use any type of leafy vegetable they want and most have only "regular Kashrut" for lettuce and cabbage based items. In fact it is very, very difficult to find Mehadrin cabbage salads on the market as practically none of the large manufacturers have it.
I did not write that all local rabbinates insist on only 'gush katif' type vegetables. What I did say was that the Israeli Chief Rabbinate requires all local rabbinates to use only 'gush katif' style bug-free produce. However, not all comply, and there is no possibility of enforcement as the local rabbinates are almost totally autonomous.
Even the more stricter and more widely accepted local Rabbanute such as Jerusalem and Rehovot will give two types of Hechschers, Mehadrin and regular, which in part is due to the type of vegetable used.
The Rabbanut in Jerusalem insists on 'gush katif' style bug-free produce for all hechshers, both mehadrin and not.