diff --git a/reference/iconv/functions/iconv.xml b/reference/iconv/functions/iconv.xml
index 3be3326c0f..de12e5c550 100644
--- a/reference/iconv/functions/iconv.xml
+++ b/reference/iconv/functions/iconv.xml
@@ -49,6 +49,15 @@
        discarded. Otherwise, <constant>E_NOTICE</constant> is generated and the function
        will return &false;.
       </para>
+      <caution>
+       <para>
+        If and how <literal>//TRANSLIT</literal> works exactly depends on the
+        system's iconv() implementation (cf. <constant>ICONV_IMPL</constant>).
+        Some implementations are known to ignore <literal>//TRANSLIT</literal>,
+        so the conversion is likely to fail for characters which are illegal for
+        the <parameter>out_charset</parameter>.
+       </para>
+      </caution>
      </listitem>
     </varlistentry>
     <varlistentry>