What is a Shorttank?

I originally posted this in Ask the Tropers but I was told to post it here instead so, here goes, I guess. I'm a little confused about what a Shorttank is exactly. My understanding is that it's a girl who is kinda tomboyish but not tomboyish enough to be a straight-up tomboy. Is that right, or am I completely off-base? Also, if that's correct, what would the difference between a Shorttank and a Girly Girl with a Tomboy Streak be, then?

Also, the page says that it's a trope mostly found in female co-leads of Shonen-oriented series. Does that mean all characters that fit this trope have to be co-leads of Shonen series? Because I've seen it used for characters who are from series that are definitely not Shonen-oriented (for instance, I saw it used for a character in Barbie Life In The Dreamhouse...) and also for characters who aren't co-leads.

Short tanks are tomboyish enough to appeal to boys and explain their role the story but are girlish enough that they arn't straight up extreme tomboy and alienating to the Periphery Demographic of actual girls. Its a common character type in Shōnen aimed at younger viewers. EDIT: this is excluding any romantic interests and anything not aimed at boys is complete misuse IMO.

Think Sora in Digimon and Misty in Pokemon which are basically the codifiers.

Tomboy with a Girly Streak is a straight up tomboy that rarely shows that they have some girly qualities. Think Chie in Persona 4 who is about as tomboy as it gets but surprisingly wore a Kimono for new years which freaked her family out that she would want to do something so girly.

edited 27th Dec '17 10:39:04 AM by Memers

Ah, okay. That makes sense. Tomboyish enough to be relatable to/appealing to boys while still girly enough for girls to relate to, essentially. Which explains why it's used mainly in media aimed at boys.

So this trope cannot be applied to characters in shows that are aimed at girls, but can this trope be applied to characters in shows that are not aimed at girls but are instead aimed at an older audience? I'm asking because I've seen it used for characters in The Flash (2014) and Legends of Tomorrow, and also for Kaylee from Firefly, and none of these are aimed at boys, IMO, but at an older, maybe gender-neutral or male audience.