How strict is United Airlines about carry on baggage?

Related questions

1. Can you check a bag with basic economy united?
2. Can I bring a backpack for basic economy united?
3. What is united basic economy?
4. Do I have to pay for baggage on United Airlines?
5. What is the baggage allowance on United Airlines?
6. Is a backpack considered a carry on United?
7. What airlines let you check bags for free?
8. Does United weigh carry on bags?
9. What if my bag is over 50 lbs united?
10. How much is first checked bag on United?

Tags

1. #other
2. #backpack
3. #maximum
4. #laptop
5. #small
6. #personal
7. #including
8. #carry
9. #dimensions
10. #handles
11. #wheels
12. #inches
13. #shoulder