How Do Tags Develop? (Also, a tag request)

I assume they just develop organically over time, unless someone either campaigns for a new tag (somehow), or someone with Steem Power begins using a tag and upvoting other posts that use it.

I would love to see a tag called "post-request" or "question" or something like that, where you could write a very simple post asking a question, and people could scroll through and see if they have some knowledge to share.

In addition to answering questions, it seems like it could help the community connect and grow.

So, for example, I'm trying to eat healthier, and I am so confused about how to make healthy choices. Here's a simple question: Does dried fruit have the same nutritional value as not-dried fruit? What about smoothies?

Any ideas about the tag idea? (Or the fruit question?)