Is there anywhere during the booking process or on the confirmation email that indicates what extras - if any - a particular code comes with?

A friend told me about a code (B920508) during this past summer that got really good rates. I used successfully twice with no issues (they always asked at check in for a 2nd card to put the liability coverage on), and I only just now realized the potential implications regarding insurance when using one of these codes (yes I'm dumb).

- If you use a code that doesn't include liability insurance and purchase as an add-on during check in, would that avoid potential issues? Or, just using a code would cause claims getting rejected?
- Is collision coverage any different (my card includes it)?

Thanks for any help! ps - I know it is almost a certainty that this has been addressed previously but I read and searched through a lot of this thread, and elsewhere online, and haven't really found a confident answer.