Well, no. What it says is that certain values must be escaped (but doesn't say which ones). Then it says there are alternate escape sequences for some values, which it lists.
It doesn't say "The following table contains the characters which must be escaped:", which would be much clearer (and actually useful).
Attached documentation patch updates the wording for bytea input escaping, per complaint by Stephen Norris above.
Joe Index: doc/src/sgml/datatype.sgml =================================================================== RCS file: /opt/src/cvs/pgsql-server/doc/src/sgml/datatype.sgml,v retrieving revision 1.119 diff -c -r1.119 datatype.sgml *** doc/src/sgml/datatype.sgml 25 Jun 2003 03:50:52 -0000 1.119 --- doc/src/sgml/datatype.sgml 25 Jun 2003 06:19:28 -0000 *************** *** 1062,1069 **** literal in an SQL statement. In general, to escape an octet, it is converted into the three-digit octal number equivalent of its decimal octet value, and preceded by two ! backslashes. Some octet values have alternate escape sequences, as ! shown in