Patch to SQLite'extension "ICU" to create collations that ignore case and accents. It adds to `icu_load_collation()` an optional third parameter that sets the collation strength (default=3).

ext_ICU_icu.c.patch

diff --git a/icu.c b/icu.c
index ae28d70..63d26b9 100644
--- a/icu.c
+++ b/icu.c
@@ -418,10 +418,14 @@ static void icuLoadCollation(
   UErrorCode status = U_ZERO_ERROR;
   const char *zLocale;      /* Locale identifier - (eg. "jp_JP") */
   const char *zName;        /* SQL Collation sequence name (eg. "japanese") */
+  int collStrength;         /* Collation strength: 0..4 (default,primary..quaternary) */
   UCollator *pUCollator;    /* ICU library collation object */
   int rc;                   /* Return code from sqlite3_create_collation_x() */
 
-  assert(nArg==2);
+  if (nArg!=2 && nArg!=3) {
+    sqlite3_result_error(p, 
+        "wrong number of arguments to function icu_load_collation()", -1);
+  }
   zLocale = (const char *)sqlite3_value_text(apArg[0]);
   zName = (const char *)sqlite3_value_text(apArg[1]);
 
@@ -436,6 +440,13 @@ static void icuLoadCollation(
   }
   assert(p);
 
+  if (nArg==3) {
+    collStrength = sqlite3_value_int(apArg[2]);
+    if (collStrength>0 && collStrength<=4) {
+      ucol_setStrength(pUCollator, collStrength-1);
+    }
+  }
+
   rc = sqlite3_create_collation_v2(db, zName, SQLITE_UTF16, (void *)pUCollator, 
       icuCollationColl, icuCollationDel
   );
@@ -471,7 +482,7 @@ int sqlite3IcuInit(sqlite3 *db){
     {"like",   2, SQLITE_UTF8,         0, icuLikeFunc},
     {"like",   3, SQLITE_UTF8,         0, icuLikeFunc},
 
-    {"icu_load_collation",  2, SQLITE_UTF8, (void*)db, icuLoadCollation},
+    {"icu_load_collation", -1, SQLITE_UTF8, (void*)db, icuLoadCollation},
   };
 
   int rc = SQLITE_OK;