See also TV movies, limited series, micro-series, Masterpiece/Mystery! and miniseries I want to see
I used to have one section for TV movies and miniseries, but eventually I decided to move the miniseries into a separate section. (Actually, I'd been thinking of doing that for some time before I finally got around to it.) A bit later, I also started a section of limited series (a concept which is commonly lumped in with miniseries). According to Wikipedia, the term "miniseries" was coined in the 1970s, and is basically limited to North America. In other places, particularly the U.K., such things are generally called serials. (Though serials are often more aptly equated with limited series.) My concept of a miniseries is something that airs more than one installment in a week; usually two or three installments, each of which is usually about two hours long (though not necessarily). However, a miniseries may be even longer than that, in rare cases up to perhaps ten installments. (I suppose it could even be more than that, but beyond ten it's hard for me to really accept the word "mini." And I rarely if ever accept the idea of a miniseries as airing over the course of more than two weeks.) If something airs on a weekly basis, the way regular series generally do, I'm more likely to consider it a limited series.
I should also say that many British serials air in the U.S. as part of PBS's Masterpiece/Mystery! series, for which I have its own section. (Other British serials may air on BBC America or other American cable networks, and those I'd likely include either in the miniseries or limited series sections, or possibly specific genre sections.) Another thing that causes confusion for me (and possibly other American viewers) is that some British serials may be aired in the U.S. in a more American-style miniseries format, over one or two (or more) weeks, but less weeks than they originally aired in the U.K., because two or more episodes may be aired here each night- even if they are aired only one night per week- as opposed to one episode per week in the U.K. Also, episodes may be edited and the story condensed for American television (which is especially frustrating). This needn't just be the case with British serials, though. After all, we do get some of our miniseries from other countries, such as Canada, Australia, or...wherever. And even some original American miniseries or limited series can be... complicated. For example, some things that are originally produced as miniseries end up airing on a single night, which makes them more likely to be labeled "TV movies." I suppose I can accept the idea of a three-hour TV movie, but this can happen even with four hour (or longer) movies. So I'll always try to put my reviews in whichever section I think they were originally intended to be.