As is today, when a vehicle with a certain cargo type car reaches a station/port/airport, if there is a nearby industry of that type, automatically the station starts accumulating that industry's output products. This may not be desirable though, especially if that station receives that specific product as raw material for another nearby industry.There should be a way to "tell" the station not to accumulate resources of a certain type (i.e. Ore) regardless of train orders.
My request is to add a way (in the station's window) to turn on/off whether the station will accumulate products from a specific nearby industry. An idea would be to see the names of all nearby industries in a new "tab", and for each one have an on/off switch (defining whether the station will receive this product). Turning the switch off should also make the "grading" of the user's company for that product in that station to disappear (either immediately or after a while) as if he never tried to serve this product.
Another, perhaps better idea (because the first one is based on in-game-user-choice and it would cause several issues - all users should agree to it, etc.) would be to automate this procedure and make it like this: check all nearby industries of each station and never receive a certain product in this station if there is a nearby industry which receives that product as raw material.