Is there any significant difference between training and pre-training, or we an have one tag for it?

I wanted to ask which method for spamming detection would be more suitable for certain scenario, Naïve Bayes or Artificial Neural Networks, but then I've found 4 sites where Bayes classifiers can be on-topic: Stats.SE -> 316 questions (1/3 unanswered), DataScience.SE -> 17 questions (4 unanswer...

Currently, I don't know what it's being used for. What should it be used for? Should we burninate it?

Is decision-theory tag basically the same as decision-making? For example, can this question: Would Google's self-driving-car stop when it sees somebody with a T-shirt with a stop sign printed on it? had decision-making tag, however it has been suggested to have one unified decision-theory. ...

By programming, I mean somebody asks about how to code AI program, e.g. Why does my NN not classify these tic tac toe pattern correctly? and the body of the question consist block of code. Are these off-topic and why they cannot be here?