Interesting. Back of the book-indexing is slightly different, but all use same theory...as what librarians learn in mandatory coursework on specialized classification and indexing theory..no matter what subject discipline.

Nowadays technology folks talk about taxonomy of complex databases and websites..which is a modern spin on....classification and indexing.

If you are anal about organizing the world to make it more understandable to others, appreciate and love applying the relationship of concepts to words within a universe of knowledge and information...then indexing is more than just ...words. It's learning about bits of the universe...from different angles.

Yes, librarians and writers (some who might enjoy this type of meticulous work and content analysis), discover a whole world of knowledge opens up to them ...

so much trivia I've picked up...I feel like the Gladman garbage bag man...I don't know how valuable this trivia is until I recycle it/reuse it for future jobs in completely different sectors. Believe me there are interrelationships amongst medicine, engineering, accounting, law, management and adult education --all sectors where I've done indexing and secondary research.