TV rules?

In my English class we had to read a short story called “Thin Gruel”. One of the main points in this story is how to be able for books to be published they have to follow certain roles. These different rules included things like showing girls as peaceful, emotional and warm. It also said having women as stay home mothers, cooking, and cleaning was not aloud. These all were considered to be stereotypical of women. It also talked about boys being per traded as brave, strong, rough, competitive, and easy going. This is just a small part of the guild lines that have to be fallowed. This list continues with how racism is also shown in different ways like, having people of color as universally athletic, as gangsters, criminals, or being angry.
So, then during our mass media class on Wednesday I was wondering if this could be related to what we talked about. We learned about light viewers and heavy viewers. How heavy viewers took what they watched and portrayed it as the truth. One of the examples that Mr.Rudd gave us in class was that the heavy viewers that see (for example) Latinos on TV see them as- people with no jobs, and less populated. When in truth we know this is not always necessarily correct.
Putting my points together it comes down to a question. If for children books there are such streaked roles to fallow. How come TV doesn’t have to follow any such rules? Or does it? If there is what are the rules and how do they work?