Any way to interpret blanked out users?

I've been confused by the blanked out username phenomenon on occasion. As far as I can tell, it can mean any of the following;

User predated the 'real names' policy and didn't comply because who knows why..
.
User was banned.

Perhaps it can also mean 'user deleted their account?'

Sometimes, I come across posts with external contact info, and think I would like to get in touch with this person, but the name is blanked. I'm left wondering if the person I'm about to email was banned because they are a jerk, or if there is some other reason behind their blanked name.

It's blanking confusing me! Is there any way to see more info? Mousing over just gets me 'this account has been retired.' Well yes, but by the user, or an admin?

The blanked name is generally because the name doesn't meet the requirements of the naming policy.

Not all retired accounts have their names blanked, and not all blanked names have retired accounts.

Long ago when this forum was first started we did not have the naming policy that we have now. When we switch to the naming policy there were a lot of users that haven't been here for several years and they didn't know that there was a change in policy.

There were also a few people that were here during the change and they opted out of the change... In other words they decided to not be part of this community anymore.

For a long time people continued to make creative names. We finally got a software update that allowed us to black out the old names and that reduced creative names by a factor of 10.

Once in a while somebody is still creates a name that does not meet our naming policy and they refused to change it so there account is closed and their name is blacked out.