What was the parsimonious design principle cited by Knuth

Don Knuth, in Volume 1 of the Art of Computer Programming, cited an engineering principle where in good design employs the same component in a variety of different contexts. His example was the Atlas Rocket which used a paper think fuel tank to provide both containment for the fuel and structure for the airframe. My copies of Knuth (I have three or four of various editions)are inaccessible. I'd like the name of the principle for a slide in a presentation I am putting together. Can someone assist?