diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml
index 918d91a05c..30f57e5ccf 100644
--- a/doc/src/sgml/syntax.sgml
+++ b/doc/src/sgml/syntax.sgml
@@ -340,17 +340,23 @@ A comment beginning with "/*" extends to the first occurrence of "*/".
Names
- Names in SQL are sequences of less than NAMEDATALEN alphanumeric characters,
- starting with an alphabetic character. By default, NAMEDATALEN is set
- to 32 (but at the time the system is built, NAMEDATALEN can be changed
- by changing the #define in
- src/backend/include/postgres.h).
- Underscore ("_") is considered an alphabetic character.
+ Names in SQL must begin with a letter
+ (a-z) or underscore
+ (_).
+ Subsequent characters in a name can be letters, digits
+ (0-9),
+ or underscores. The system uses no more than NAMEDATALEN-1 characters
+ of a name; longer names can be written in queries, but they will be
+ truncated.
+ By default, NAMEDATALEN is 32 so the maximum name length is 31 (but
+ at the time the system is built, NAMEDATALEN can be changed in
+ src/include/postgres_ext.h).
Names containing other characters may be formed by surrounding them
- with double quotes. For example, table or column names may contain
+ with double quotes ("). For example, table or column
+ names may contain
otherwise disallowed characters such as spaces, ampersands, etc. if
quoted. Quoting a name also makes it case-sensitive,
whereas unquoted names are always folded to lower case. For example,
@@ -359,6 +365,12 @@ A comment beginning with "/*" extends to the first occurrence of "*/".
considered the same by Postgres, but
"Foo" is a different name.
+
+
+ Double quotes can also be used to protect a name that would otherwise
+ be taken to be an SQL keyword. For example, IN
+ is a keyword but "IN" is a name.
+