An indexed collection of 3-D images (or templates) from which Raman artifacts could be synthesized (See Rama).
The actual catalog was a grouping of crystal pillars which holographically displayed available items. One column contained dozens of images.
Some items on display were identified as domestic utensils (knives, forks, et cetera), hand tools, scientific instruments, and Raman body harnesses. There were, however, thousands of artifacts in the catalog.
It is assumed that when a Raman required an item on display, it could be manufactured from a template coordinated to the holographic image. The raw materials would be taken from the cylindical sea, and the item manufactured as Biots were.From Rendezvous With Rama by Arthur C. Clarke