I'm looking through Apache access logs, trying to remember what HTTP code 301 is. I have O'Reilly's _HTTP: The Definitive Guide_. I look in the index, and I see that 301 is aggregated with bq. 300-399 status codes, 61-64, 502 Why not spell out all the codes? bq. 301 status code, 61, 502 302 status code, 61, 502 303 status code, 62, 502 For that matter, why not have the index include the answer I want? bq. 301 status code: Moved Permanently, 61, 502 I could have the answer right there, without having to go any further. Further, the book has more than 600 pages, so I could even be able to look on page 301 and find out. It could have a footnote on the bottom of page 301 saying "301: Moved Permanently. Turn to pages 61-64, 502 for more information." Alas, I think that Chris Shifflet's purple HTTP book is half the pages, so that wouldn't do there.