As some have said, funerals are not for the dead. They are for those left behind. Dress to show respect for the one's who have lost a loved one. The dead do not care. You show who you really are when attending a funeral.
^^This^^
I suppose I should have included the word "character" when I started off the thread. Reading through the posts I see that some never or seldom attend funerals and that's okay. Seems I have attended a great number of funerals in recent years and I've been to many traditional as well as less than traditional ceremonies.
Adhering to the deceased's or family's requests, or thoughtfully responding in such a way that reflects the life of the guest of honor that may not be traditional is indeed honoring them and showing respect. For example, I too have been to
many a farmer's funeral here in Arkansas where most of the male attendees were wearing bib overalls. I assure you, though, they were their cleanest pair, and they also left their favorite hunting dog out in the back of the truck.
I've also been to funerals where most people showed up loud and proud riding a Harley and wearing leather gear. Based on the situation, this was very respectful.
I even attended the funeral of a long time state wildlife officer where most everyone wore hunting camo . . . this was quite appropriate.
I raised my sons to be respectful, as I learned from my father. I don't suppose there are any rules that you have to show up at a traditional funeral in a black suit in tie, though out of respect I usually do. But showing up at a traditional funeral dressed like a bum (not because they're poor, but because they lack character) or bringing along your lap dog inside the church demonstrates crassness.