What is the difference between a Catholic custom and a Catholic tradition?

**What is the difference between a Catholic custom and a Catholic tradition?** I have noticed a trend in recent years to call Catholic customs a Catholic tradition (with a small t). Much confusion is out there in this domain. Tradition with a capital T is less confusing for most with what a tradition with a miniscule t actually is. The confusion I am seeing lately is confusing Catholic traditions with Catholic customs and Catholic devotions. There is a French author out there that really explained this quite well and stated that a Catholic custom could not be considered a Catholic tradition (local) if it has not been around for less than 100 years. Unfortunately, I can not recall the source. Any clarification would be greatly appreciated. I imagine some local customs are now considered true local traditions.