The document outlines a proposal for a tool called CnP to detect and prevent errors from copy-and-pasted code during software development. It describes how copy-pasted code can lead to inconsistencies when modified. It then details a proof-of-concept tool called CReN that tracks copy-pasted code, automatically renames identifiers consistently across clones when modified, and demonstrates how it could catch errors in examples from literature. It proposes evaluating CReN and exploring using it to detect other types of inconsistencies from copy-pasted code.