I've noticed that a number of the series that i have covered are a single series long with 12-20 episodes in total, usually 15 episodes. The problem is that i'm not sure how to list them on the site. Are they mini series or TV series? What's the logic here?

Thanks.

Apparently a miniseries is a series with a predetermined number of episode (i.e. that ends, not potentially to be renewed with another season), and which is up to 12 episodes (I thought it was around 8).
I'm not sure that the difference is very important though

I see.
Thanks for clearing things up, I'll bear it in mind for future additions.