diff options
| -rw-r--r-- | doc/src/sgml/func/func-string.sgml | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/doc/src/sgml/func/func-string.sgml b/doc/src/sgml/func/func-string.sgml index 3eec93eb339..01cc94c234e 100644 --- a/doc/src/sgml/func/func-string.sgml +++ b/doc/src/sgml/func/func-string.sgml @@ -693,12 +693,21 @@ <returnvalue>text</returnvalue> </para> <para> - Converts the first letter of each word to upper case and the - rest to lower case. When using the <literal>libc</literal> locale - provider, words are sequences of alphanumeric characters separated - by non-alphanumeric characters; when using the ICU locale provider, - words are separated according to - <ulink url="https://www.unicode.org/reports/tr29/#Word_Boundaries">Unicode Standard Annex #29</ulink>. + Converts the first letter of each word to upper case (or title case + if the letter is a digraph and locale is <literal>ICU</literal> or + <literal>builtin</literal> <literal>PG_UNICODE_FAST</literal>) + and the rest to lower case. When using the <literal>libc</literal> or + <literal>builtin</literal> locale provider, words are sequences of + alphanumeric characters separated by non-alphanumeric characters; + when using the ICU locale provider, words are separated according to + <ulink url="https://unicode-org.github.io/icu-docs/apidoc/dev/icu4c/ustring_8h.html#a47602e2c2012d77ee91908b9bbfdc063">u_strToTitle ICU function</ulink>. + </para> + <para> + This function is primarily used for convenient + display, and the specific result should not be relied upon because of + the differences between locale providers and between different + ICU versions. If specific word boundary rules are desired, + it is recommended to write a custom function. </para> <para> <literal>initcap('hi THOMAS')</literal> |