Most exclusion systems don't allow for parental permission. You can't take your 15 year old son to a movie rated NC17 or allow him to read fic with the Explicit Adult flag.
The problem with defining things by "intent to arouse" and the reason I will not accept this definition is that it requires the person judging the material to be a mind-reader. There have been many things which were not written with the particular intent to arouse that have been defined as pornography because those who were looking for pornography were aroused or feared others would be aroused by them; they then made the mental leap that if they were aroused by reading/viewing the material, it was clearly intended to arouse them. Foot fetishists are kind of the exception that proves the rule, because people who do not have foot fetishes consider bare feet a normal sight. I'm thinking more along the lines of those who are trying to decide whether an explicit scene of characters having sex was intended to arouse or not. It may be arousing to many people, but the reason it is in the story may well be that the characters interact in a way that reveals previously unseen aspects of their personalities. A reader who fails to see that will assume that the intent was to arouse.
So I find that definition completely unuseful, since I can't read people's minds, only their fic.
Re: #5
The problem with defining things by "intent to arouse" and the reason I will not accept this definition is that it requires the person judging the material to be a mind-reader. There have been many things which were not written with the particular intent to arouse that have been defined as pornography because those who were looking for pornography were aroused or feared others would be aroused by them; they then made the mental leap that if they were aroused by reading/viewing the material, it was clearly intended to arouse them. Foot fetishists are kind of the exception that proves the rule, because people who do not have foot fetishes consider bare feet a normal sight. I'm thinking more along the lines of those who are trying to decide whether an explicit scene of characters having sex was intended to arouse or not. It may be arousing to many people, but the reason it is in the story may well be that the characters interact in a way that reveals previously unseen aspects of their personalities. A reader who fails to see that will assume that the intent was to arouse.
So I find that definition completely unuseful, since I can't read people's minds, only their fic.