In Googling for the definitions, I found that it is very hard to find definitions for most of these. As a service to my readers, here are all the line items from my contract, and the best explanation I've found so far for them. Some come from Verizon or from user-forum discussions I ran across. Some are based on my own intuition and understanding of wireless technology.
Corrections are welcome and will help to make the list more complete. I don't promise that it's all correct, but I hope people with specific knowledge will be able to help me improve it and make it correct.
Updated on June 4, 2015, based on reader comments. Thanks much!
Updated on April 1, 2019, based on the receipt we got when we upgraded one of our phones last July.