Rule Definition
A program with a lot of duplication is hard to change. It might be required to change every copy of a copy/pasted code while it is very difficult to locate these copy/pasted code elements. Copy-and-paste is not always bad for a quick urgent "hack", but it is always a very dangerous practice in the long run.
Remediation
Try to reduce the Copy-Pasted Artifacts.
Reference
Standard suggestions based on CAST Quality Model
Related Technologies
Technical Criterion
Architecture - Reuse
About CAST Appmarq
CAST Appmarq is by far the biggest repository of data about real IT systems. It's built on thousands of analyzed applications, made of 35 different technologies, by over 300 business organizations across major verticals. It provides IT Leaders with factual key analytics to let them know if their applications are on track.