Front/back on rail features only refers to the position of the feature relative to you, on the approach. If the feature is on your toeside, it's frontside. If it's heelside, then the trick is said to be backside.
Taking a step back for a second... a boardslide is a sideways slide where the nose passes over the feature first, a lipslide the tail passes over the feature first. A front boardslide will have your butt facing down hill once you're on the feature -- and so will a back lipslide! Likewise, a front lipslide you're facing down the hill, same as a back boardslide. Confusing? Kinda. Just remember that front/back refers to the features position, not what direction you're facing.
Nose/Tailslide is just like an off-center boardslide. If you're a regular rider, approaching backside and sliding on the tail of your board, it's a backside tailslide. But it has nothing to do with which direction you're facing
@liner if you're going *over* the feature yeah it's either a crook or a blunt slide, the difference being with a blunt slide you're more like a "pressed" position with the nose elevated a bit.