The reason I asked was because in an article in the Nov 2004 Business and Commercial Aviation, it said "It should be noted that unless all surfaces are aerodynamically clean, the aircraft must first be de-iced with type I fluid."
However this is in a paragraph about protecting aircraft parked for extended periods of time. Apparently some operators use fluids if an aircraft is parked.
It also says that "all type II/IV fluid must be removed with Type I fluid before departure if the parking time has exceeded four hours"
Anyone familiar with these practices.