It's possible that you might be encountering it in a specific context that hasn't been explained. Could you provide more information about where you saw this term? For example:
* What are you trying to do? What is the overall task or problem you're working on?
* What technology are you using? Are you working with a specific programming language, networking protocol, or software?
* Can you provide the context? What was the sentence or paragraph where you saw the term "transparent prefix"?
With more context, I can help you understand what "transparent prefix" might mean in your situation.