In the arctic and tropical climates, office towers will accept food.
Configuration file: officefood
Command line: -O
In the tropic and arctic climates, the office towers by default accept passengers, mail and goods. This sometimes prevents a city from growing further, because it doesn't accept food at all.
With this switch, all the office towers accept an amount of food that is calculated by (passengers+goods)/4, rounded down. So an office tower accepting 4/8 passengers and 1/8 goods would accept 1/8 food too.
Note that this doesn't show up in the query tool, but it is taken into account when determining what a station will accept.