diff --git a/reference/strings/functions/quoted-printable-decode.xml b/reference/strings/functions/quoted-printable-decode.xml
index 369b31d839..1d5b8b87a5 100644
--- a/reference/strings/functions/quoted-printable-decode.xml
+++ b/reference/strings/functions/quoted-printable-decode.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.2 $ -->
+<!-- $Revision: 1.3 $ -->
 <!-- splitted from ./en/functions/strings.xml, last change in rev 1.2 -->
   <refentry id="function.quoted-printable-decode">
    <refnamediv>
@@ -16,7 +16,11 @@
      </methodsynopsis>
     <simpara>
      This function returns an 8-bit binary string corresponding to the
-     decoded quoted printable string.  This function is similar to
+     decoded quoted printable string (according to
+     <ulink url="&url.rfc;2045">RFC2045</ulink>, section 6.7, not
+     <ulink url="&url.rfc;2821">RFC2821</ulink>, section 4.5.2, so additional
+     periods are not stripped from the beginning of line).
+     This function is similar to
      <function>imap_qprint</function>, except this one does not
      require the IMAP module to work.
     </simpara>