# Documentation or comments can be a knowledge duplication
If you're writing comments on your code expressing what the code does, when the code is perfectly expressing what it does, that's a duplication.
# Backlinks
- DRY helps forgetting
- For example, you might be documenting rigorously about how your code works, even when your code is already expressing well on how it works. When you need to change your code, you'll need to remember to update your documentation as well (Documentation or comments can be a knowledge duplication).
- DRY misconceptions