What were the guidelines of the Hays Code? A Wikipedia article describes the three basic principles:
1. No picture shall be produced that will lower the moral standards of those who see it. Hence the sympathy of the audience should never be thrown to the side of crime, wrongdoing, evil or sin.
2. Correct standards of life, subject only to the requirements of drama and entertainment, shall be presented.
3. Law, natural or human, shall not be ridiculed, nor shall sympathy be created for its violation.
Watching just a few of these films will give you an idea of why the codes were implemented, and why they were so unnecessary. These pre-code films did depict drug use, characters who lost their faith, and characters who walked on both sides of the law. But they often did so in a realistic way, not in a manner meant to influence the audience down a path of moral decay. What you see in these films is excellent storytelling, and sometimes to tell a good story, you have to sympathize with the "devil." Take the film "Midnight Mary" for example. It's all about a woman who keeps getting caught up with the mob, and seems to be constantly followed by trouble. It's not that she loves being on the wrong side of the law, but she can never seem to make it as a "good girl," no matter how hard she tries. She simply gets tired of trying after a while: a perfectly human reaction, but of course, a supposedly "dangerous" one if the audience were to sympathize with her. This is not to say that everything was fast and free in the pre-code days. Even "Midnight Mary" was originally to be named "Lady of the Night," but that title was deemed too provocative.
If you're looking for a special feature that will point out the pre-code moments and fully explain the history around it, that's not exactly here. What this set does have is great commentary by filmmakers and experts. They do occasionally explain moments that are distinctly pre-code, but they also fit in a whole lot more. It may be odd in comparison with the director/actor commentaries on most films, but these sound like they were scripted and rehearsed. They squeeze in so many facts about the films and so much background about the actors that it's actually pretty amazing. There's no time for coughing or talking about the donuts someone brought to the studio that day, it's all business here.
In addition to the full feature length films, there are also extras like short cartoons and short-reel productions. There is a warning that accompanies one of the cartoons that I thought was very well worded. It basically warned that while the stereotypes and the racist attitudes portrayed in the film were never excusable, to hide them away and pretend they never existed would be even worse. It's an excellent attitude to take when you're putting together a DVD that deals with censorship.
What strikes me about many of the films in this set is the relevance to modern audiences. There are scenes from "Other Men's Women" that seem like they could be reshot in color scene for scene and they would work today. There's a quirkiness to the characters, subtle sarcasm, and sexuality that isn't whitewashed over. Movies like these might make you look at your grandparent's time a little differently. Overall, this is an entertaining group of films, and a great resource for anyone interested in early Hollywood films and censorship.