G930700 is the discount code for IBM employees. There's a decent chance you will be asked at the rental counter for employee ID. If you can't produce it, you will be charged the walk-up rate which is going to be significantly higher than what you booked at. It's probably not worth the risk when there are so many legitimate public discount codes out there that you qualify for.

I don't know off-hand if the IBM Avis discount automatically adds LDW, but if it does and you get into an accident, that would be another source of problems. There's a good chance your credit card and/or own personal insurance would then cover any damage, but it could put you in an uncomfortable situation.