I've only seen dogleg boxes in RWD cars. They're mainly found in cars built around 1980.
It's a 5 speed box with reverse located above 1st, 2nd above 3rd & 4th above 5th.
It makes for a convenient change from 5th back to 4th when crusing on the open road.
When driving off road & stuck in mud, sand etc. the change from 1st to reverse is easy, enabling you to quickly get the car rocking & drive out.
Notable cars that had dogleg boxes are:
Nissan Silvia with FJ20
Vauxhall Chevette 2.3L (5th gear was 1:1)
Mercedes, the small car made around 1985, specifically the model with the cosworth head