Minhag in the truest sense is in the LOCATION of a place. If in a certain place, (city, maybe even big neighborhood or even inside a Shul) certain things are expected and said to be like that, if it doesn't contradict Halacha then it can be categorized as a Minhag. For example let's say that in a certain city they decide that they will make a limit on the amount of the price of a wedding (so that people do not overspend their money on these things and instead focus more on having more children and not being bogged down in debt, and/or not embarrassing the people that have less money and cannot afford extravagant weddings) . This would be a Minhag of that particular city. Those who move into this city are expected to follow its Minhagim and Takanot.