What is a Hack?

A "hack" in a codebase doesn't have any relation with actual "hacking" it is an often improvised solution that solves a problem but isn't a proper solution. It's a kind of shortcut or a makeshift fix intended to make something work temporarily or to get around a particular issue.

In essence, it's like using duct tape for a DIY project: it can hold things together, but it might not be the most reliable or stable solution.

Why is it in the documentation?

Hacks by their nature are often hard to understand if you don't already know what they are. And sometime understanding why a hack has been made instead of a proper solution is necessary to make that proper solution. This is the reason documenting the why, how and when of hacks is crucial.

But if it works, it works, right?

Yes, if it works, it works... except when it doesn't.

Hacks are a form of technical debt and like any kind of technical debt they should be avoided when possible and reduced over time.