A shove knife is most often used on:

A shove knife is specifically designed for the purpose of manipulating locks, particularly those found on outward-swinging doors. This tool is adept at sliding between the door and the frame to disengage the lock mechanism without triggering any internal mechanisms or causing damage to the door itself. The design and functionality of the shove knife make it ideal for gaining entry in situations where traditional methods may be less effective or applicable.

In contrast, the other types of openings, such as sliding doors and windows, casement windows, and double-hung windows, typically have different lock mechanisms that do not lend themselves to the same approach as that used with outward-swinging doors. For instance, sliding doors often require a different technique due to their horizontal movement, while casement and double-hung windows have window-specific locking systems that would not benefit from the shove knife's design. Thus, the shove knife is optimally suited for use on outward-swinging doors, making it the correct choice.