They are also that, as I understand it. That's how the training data is represented, and how the neurons receive their weights. This is just leaning on the scale after the model is already trained.

There are several ways to go about it, like (in order of effectiveness): train your model from scratch, combine a couple of existing models, finetune an existing model with extra data you want it to specialise on, or just slap a system prompt on it. You generally do the last step at any rate, so it's existence here doesn't proof the absence of any other steps. (on the other hand, given how readily it disregards these instructions, it does seem likely).

Some of them let you preload commands. Mine has that. So I can just switch modes while using it. One of them for example is "daughter is on" and it is to write text on a level of a ten year old and be aware it is talking to a ten year old. My eldest daughter is ten