I don't think this is a good idea because the more fields you add, the more unusable will Mantis become for its users. Guess what they think when you want to implement it in your company and everybody says, oh gosh, how many fields do I have to fill in there, perhaps I'll rather talk to you on the phone.

The barriers to submitting a bug report just have to be extremely low, or nobody will use the thing.

Actually I even think the severity field should be an option, not required.

I think I'm going to start populating the option lists with a valid default selection. That way the only two fields required would be Summary and Description. This only treats the symptoms of the (sometimes unsolvable) problem of having uneducated reporters. But it may help.

Implemented basic private/public bugs. Viewing threshold is set in the config file so only original reporter and those users matching the threshold can see it.