diff -U3 /home/postgres/postgres/contrib/dict_xsyn/expected/dict_xsyn.out /home/postgres/postgres/build/testrun/dict_xsyn/regress/results/dict_xsyn.out
--- /home/postgres/postgres/contrib/dict_xsyn/expected/dict_xsyn.out	2026-01-12 18:46:10.651710164 +0000
+++ /home/postgres/postgres/build/testrun/dict_xsyn/regress/results/dict_xsyn.out	2026-01-12 18:49:00.689933527 +0000
@@ -1,11 +1,14 @@
 CREATE EXTENSION dict_xsyn;
 -- default configuration - match first word and return it among with all synonyms
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=true, MATCHORIG=true, KEEPSYNONYMS=true, MATCHSYNONYMS=false);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 --lexize
 SELECT ts_lexize('xsyn', 'supernova');
-        ts_lexize         
---------------------------
- {supernova,sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
@@ -22,10 +25,13 @@
 
 -- the same, but return only synonyms
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=false, MATCHORIG=true, KEEPSYNONYMS=true, MATCHSYNONYMS=false);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
-   ts_lexize    
-----------------
- {sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
@@ -42,16 +48,19 @@
 
 -- match any word and return all words
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=true, MATCHORIG=true, KEEPSYNONYMS=true, MATCHSYNONYMS=true);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
-        ts_lexize         
---------------------------
- {supernova,sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
-        ts_lexize         
---------------------------
- {supernova,sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'grb');
@@ -62,16 +71,19 @@
 
 -- match any word and return all words except first one
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=false, MATCHORIG=true, KEEPSYNONYMS=true, MATCHSYNONYMS=true);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
-   ts_lexize    
-----------------
- {sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
-   ts_lexize    
-----------------
- {sn,sne,1987a}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'grb');
@@ -82,6 +94,9 @@
 
 -- match any synonym but not first word, and return first word instead
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=true, MATCHORIG=false, KEEPSYNONYMS=false, MATCHSYNONYMS=true);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
  ts_lexize 
 -----------
@@ -89,9 +104,9 @@
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
-  ts_lexize  
--------------
- {supernova}
+ ts_lexize 
+-----------
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'grb');
@@ -102,6 +117,9 @@
 
 -- do not match or return anything
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=false, MATCHORIG=false, KEEPSYNONYMS=false, MATCHSYNONYMS=false);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
  ts_lexize 
 -----------
@@ -122,16 +140,19 @@
 
 -- match any word but return nothing
 ALTER TEXT SEARCH DICTIONARY xsyn (RULES='xsyn_sample', KEEPORIG=false, MATCHORIG=true, KEEPSYNONYMS=false, MATCHSYNONYMS=true);
+ERROR:  Unicode case folding can only be performed if server encoding is UTF8
+CONTEXT:  line 1 of configuration file "/home/postgres/postgres/build/tmp_install/usr/local/pgsql/share/tsearch_data/xsyn_sample.rules": "# Sample rules file for eXtended Synonym (xsyn) dictionary
+"
 SELECT ts_lexize('xsyn', 'supernova');
  ts_lexize 
 -----------
- {}
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'sn');
  ts_lexize 
 -----------
- {}
+ 
 (1 row)
 
 SELECT ts_lexize('xsyn', 'grb');