...see ModelingTrap (using SpellingRuleDoubledConsonant)
This used to drive me up the wall: I used to be a member of a team called the "Modelling Team" (as in propagation modelling), and at a BigDesignUpFront shop too, so there was a lot of modelling (as in OO) going on too. Could we convince our (US sourced) document preparation system that we wanted two 'l's? We could not.
In the U.S., "Modelling" would be pronounced Mo-del'-ling, whereas we want Mo'-de-ling. So we don't double the consonant as we want the accent to stay on the first syllable. Is this different in "British" (or "Commonwealth") spelling countries?
Apparrently so.