There are many similarities between catalogers and programmers. These are just the few that come most easily to mind.

1) Catalogers are used to precisely following complicated and arcane rules for creating catalog records, much like the syntax rules for programming languages.

2) Catalogers and programmers both appreciate the value of applying consistent style conventions and standards.

3) Documentation! Catalogers are used to wading through extensive and complicated online documentation to use OCLC products and Library of Congress Documentation. Once you have mastered these tools, the MSDN and Java API pages don't look so overwhelming.

4) Applying metadata is really just embedding cataloging into digital objects.

5) Authority control is all about standardizing naming conventions for terminology to increase search precision and recall.

6) Upgrades, new standards, change! Just when you are getting really comfortable with the latest cataloging standards and automation tools the standards evolve and there is an upgrade. It comes with the territory.

7) Catalogers maintain a big picture view of how their collection is organized and indexed while also paying close attention to the minute details of each catalog record, like programmers with their code.

8) Catalogers see the world as a vast taxonomy of sets, subsets and interrelationships. Programmers see the world as made up of classes, subclasses and interfaces.

9) A bibliographic work is to an edition as a class is to an object. One is an instantiation of the other. (Librarians speak object orientation, they just don't realize it. What else is FRBR?)

10) Catalogers have been analyzing how to optimize "search" before computers were created.