[searchableguy]

What is a last in first out rule?

[floren]

Layoffs start from the most-recently-hired employee and work back by seniority.

[searchableguy]

This is required by government and why?

[sofixa]

To avoid companies laying off the most experienced employees and replacing them with new grads to lower costs as a regular practice.

There are ways of doing it, it's just slightly more complicated than just doing it directly.