To violently rub your hand into somebody's hair whilst shouting "FLAAAANNNAAAGGGE" causing their hair to become very out of place or 'flanned'. Originated in the North East of England.
Making plans that one does not intend to keep. It is flake planning. The purpose of flanning is to make it seem to the other person that you like them and want to spend time with them, when in reality you are hoping they cancel first so you don't have to see them.
When two people flan with each other, it becomes a game of chicken, each one waiting for the other to break and cancel first.
Scott bumped into Billy on the street after not seeing him for 3 years. They both enthusiastically agreed to have lunch and play racquetballin the near future, but I think they were both flanning.