The following documentation comment has been logged on the website: Page: https://www.postgresql.org/docs/18/sql-syntax-lexical.html Description:
Why repeat information within the same section? In Section 4.1.1, “Identifiers and Keywords”: >> The option with identifiers in quotation marks allows you to include escaped Unicode characters identified by their code points. This option begins with U& (an uppercase or lowercase U followed by an ampersand) immediately before the opening double quotation mark, with no spaces between them, for example, U&“foo”. (Note that this creates ambiguity regarding the & operator. To avoid this problem, use spaces around the operator.) Inside the quotation marks, Unicode characters can be specified in escaped form by writing a backslash followed by the character’s four-digit hexadecimal code, or, alternatively, a backslash followed by a plus sign, followed by the character’s six-digit hexadecimal code. For example, the identifier “data” can be written as follows: > U&“d\0061t\+000061” ... .... This information, along with examples, is also provided in Section 4.1.2.3. String Constants with Escaped Unicode Characters >> PostgreSQL also supports another type of string escape syntax that allows you to specify arbitrary Unicode characters by code point. A Unicode-escaped string constant begins with U& (an uppercase or lowercase U followed by an ampersand) immediately before the opening quote, with no spaces between them, for example, U&“foo”. (Note that this creates ambiguity with the & operator. To avoid this problem, use spaces around the operator.) Inside the quotes, Unicode characters can be specified in escaped form by writing a backslash followed by the four-digit hexadecimal code of the character, or, alternatively, a backslash followed by a plus sign, followed by the six-digit hexadecimal code of the character. For example, the string “data” can be written as follows: > U&'d\0061t\+000061' ... ....
