Root + Impact

Description

• The custom error error notRegistered(); is declared but never used anywhere in the contract. Solidity reserves a storage slot for error selectors in the bytecode metadata, slightly increasing deployment byte size and gas cost.

Risk

Impact:

• Minimal gas impact (~200–300 bytes extra in deployed code). However, it creates code clutter and reduces readability.

Proof of Concept

Recommended Mitigation

Remove the unused error definition to reduce bytecode size and maintain cleaner, optimized code.