The following bug has been logged on the website:
Bug reference: 6639
Logged by: Ian
Email address: iain.dalton@gmail.com
PostgreSQL version: 9.1.3
Operating system: GNU/Linux
Description:=20=20=20=20=20=20=20=20
The URL http://www.postgresql.org/docs/9.1/interactive/notation.html lays
out the notation used in the rest of the book, but it appears to be out of
date with the stylesheet, as the differences noted in the subject apply.