# Commented-out code

*Code nobody needs*: one of the ways AI coding agents bloat software, from lessloc's [pattern catalog](https://lessloc.org/patterns/index.md). lessloc catches it as [`commented-out`](https://lessloc.org/guide/reference.md#tier-0) and refuses it before it lands.

## What makes commented-out code a bad practice?

The standards that call it a bad practice: [CWE-1085](https://cwe.mitre.org/data/definitions/1085.html); Clean Code C5; Sonar S125.

## What does lessloc do about commented-out code?

lessloc catches it as [`commented-out`](https://lessloc.org/guide/reference.md#tier-0) and refuses it before it lands.

- `commented-out` (tier 0): Commented-out code. Refused before it lands.

## Related patterns

The other patterns in [Code nobody needs](https://lessloc.org/patterns/index.md#code-nobody-needs):

- [Options, flags, parameters or config for needs nobody named](https://lessloc.org/patterns/speculative-options.md): lessloc gives every session a rule against it and catches it as `mode-flag`.
- [An interface or abstract class with one implementation](https://lessloc.org/patterns/single-impl.md): lessloc catches it as `single-impl`.
- [Wrappers that only forward; barrel files that only re-export](https://lessloc.org/patterns/wrappers.md): lessloc catches it as `wrapper`.
- [A new function or import that nothing calls or tests](https://lessloc.org/patterns/unused.md): lessloc catches it as `unused` (ruff adds unused variables).
- [Obsolete code kept behind a guard or flag instead of deleted](https://lessloc.org/patterns/guarded-dead-code.md): lessloc gives every session the rule: delete what the change makes dead.
- [Tombstones](https://lessloc.org/patterns/tombstones.md): lessloc catches it as `history`.
- [Stubs and fake success](https://lessloc.org/patterns/stubs.md): lessloc catches it as `stub`; it asks to finish the code or to tell the user what is not real yet.
- [Placeholders: # ... existing code ..., "your code here"](https://lessloc.org/patterns/placeholders.md): lessloc catches it as `placeholder` and refuses it before it lands.
- [Debug leftovers](https://lessloc.org/patterns/debug-leftovers.md): lessloc catches it as `debug-leftover`.
- [A demo \_\_main\_\_ block or demo folder nobody asked for](https://lessloc.org/patterns/demo-code.md): lessloc catches it as `demo-code` and `new-folder`.
- [Hand-written boilerplate a language feature writes](https://lessloc.org/patterns/boilerplate.md): lessloc catches it as `simpler`.
- [A one-line helper used once](https://lessloc.org/patterns/single-use.md): lessloc catches it as `single-use`.
- [TODO and FIXME left behind](https://lessloc.org/patterns/todo.md): lessloc catches it as `todo`; it asks to finish the work, or to record known debt as `shortcut:` and tell the user.