diff --git a/reference/strings/functions/strspn.xml b/reference/strings/functions/strspn.xml
index 8c7dfaff82..7b5345af2c 100644
--- a/reference/strings/functions/strspn.xml
+++ b/reference/strings/functions/strspn.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.9 $ -->
+<!-- $Revision: 1.10 $ -->
 <refentry xmlns="http://docbook.org/ns/docbook" xml:id="function.strspn">
  <refnamediv>
   <refname>strspn</refname>
@@ -59,6 +59,7 @@ $var = strspn("42 is the answer, what is the question ...", "1234567890");
      <listitem>
       <para>
        The start position of the string to examine.
+       Negative value counts position from the end of a string.
       </para>
      </listitem>
     </varlistentry>
@@ -67,6 +68,7 @@ $var = strspn("42 is the answer, what is the question ...", "1234567890");
      <listitem>
       <para>
        The length of the string to examine.
+       Negative value sets length from the end of a string.
       </para>
      </listitem>
     </varlistentry>