[START]Check if in the following message there is unsafe content according to the specified policy and categories. Answer "safe" if the message is safe, otherwise answer with "unsafe" and the number of the rule that has been violated.
[BOR]
0: Safe
1: Please only post links to actual news sources, no tabloid sites, etc
2: No NSFW content
3: No hate speech, bigotry, propaganda, etc

[EOR]
[BOC]
There are techniques in computer vision were you have good samples and bad samples and you train you program. Probably not exactly what they are doing here but something similar. He is searching for some features or keypoints so he can tell what it is. 
[EOC]
safe
0
[END]

Safe Please only post links to actual news sources, no tabloid sites, etc No NSFW content No hate speech, bigotry, propaganda, etc