Three characters, .org, X-to-Y. M2F reads as manufacturer to factory, market to farm, or mission to field.
Market to farm is a real and growing idea: shortening the distance between producers and buyers, which is the premise behind farm-to-table platforms, cooperative marketing bodies, and agricultural development programmes. On the .org it fits a cooperative, a food policy organisation, or a rural development initiative.
Mission to field suits humanitarian and faith organisations, where the phrase describes the actual operational chain from headquarters to the people doing the work.
The X-to-Y form is what makes short strings work. Three letters alone are a code. Three letters with a preposition in the middle are a relationship, and readers hold relationships in memory far better than they hold codes.
Three characters on a major extension, permanently scarce, and legible to an institutional audience.
Enquiries welcome.