How to know if a character can attack from "rear"?

[Godkiu]

For example, Nowa can attack from rear but Lugo and Yusukr can't. Where can I check that?

[Pheace]

The way I assumed it worked was Short is only front, Medium is both front and rear, and long is only rear. (granted, not 100% sure here)

[Laurence I of Yharnam]

I want to add that there are small icons with S,M and L next to the characters stats which tells you.

[Harvest]

Short (S) range characters can only attack if placed in the front row and only target enemies in the front row.
Medium (M) range characters can attack in the front and back row. If placed in the front row, M range characters can target enemies in the front and back row. If placed in the back row, M range characters can only target enemies in the front row.
Long (L) range characters can attack enemies in the front and back row regardless of where the characters are placed in formation.

[DD The Pumpkin King]

You're pretty close.

S red- can hit row 1 from the front.

M yellow- can hit row 1 and 2 if they're placed on the front but only row 1 if placed in the rear.

L blue- can hit row 1 and 2 from anywhere.

[Pnume]

In the character selection if you try to put a character on a position from where he can't attack you'll see on his card a sword inside a barred circle