diff --git a/reference/stream/functions/stream-copy-to-stream.xml b/reference/stream/functions/stream-copy-to-stream.xml
index 2e26b6e79ca7..b426fc175447 100644
--- a/reference/stream/functions/stream-copy-to-stream.xml
+++ b/reference/stream/functions/stream-copy-to-stream.xml
@@ -14,14 +14,14 @@
    <methodparam choice="opt"><type class="union"><type>int</type><type>null</type></type><parameter>length</parameter><initializer>&null;</initializer></methodparam>
    <methodparam choice="opt"><type>int</type><parameter>offset</parameter><initializer>0</initializer></methodparam>
   </methodsynopsis>
-  <para>
+  <simpara>
    Makes a copy of up to <parameter>length</parameter> bytes
-   of data from the current position (or from the
-   <parameter>offset</parameter> position, if specified) in
-   <parameter>from</parameter> to <parameter>to</parameter>. If
-   <parameter>length</parameter> is &null;, all remaining content in
+   of data from <parameter>from</parameter> to <parameter>to</parameter>,
+   starting at the current position in <parameter>from</parameter>, or at
+   <parameter>offset</parameter> if it is greater than <literal>0</literal>.
+   If <parameter>length</parameter> is &null;, all remaining content in
    <parameter>from</parameter> will be copied.
-  </para>
+  </simpara>
  </refsect1>
 
  <refsect1 role="parameters">
@@ -55,9 +55,16 @@
     <varlistentry>
      <term><parameter>offset</parameter></term>
      <listitem>
-      <para>
-       The offset where to start to copy data
-      </para>
+      <simpara>
+       If greater than <literal>0</literal>, the position in
+       <parameter>from</parameter>, counted from the start of the stream,
+       at which to start copying: <parameter>from</parameter> is first moved
+       to that position, as with <function>fseek</function> and
+       <constant>SEEK_SET</constant>.
+       If <literal>0</literal> (the default) or negative, no seek is
+       performed and copying starts at the current position in
+       <parameter>from</parameter>.
+      </simpara>
      </listitem>
     </varlistentry>
    </variablelist>
@@ -115,6 +122,22 @@ echo stream_copy_to_stream($src, $dest2) . " bytes copied to remainder.txt\n";
   </para>
  </refsect1>
 
+ <refsect1 role="notes">
+  &reftitle.notes;
+  <note>
+   <simpara>
+    When <parameter>from</parameter> is a socket stream in blocking mode,
+    copying stops as soon as no data is received within the stream timeout,
+    even if the end of the stream has not been reached.
+    &false; may then be returned, even though the data read until then has
+    already been written to <parameter>to</parameter>.
+    This timeout defaults to
+    <link linkend="ini.default-socket-timeout">default_socket_timeout</link>
+    and can be changed with <function>stream_set_timeout</function>.
+   </simpara>
+  </note>
+ </refsect1>
+
  <refsect1 role="seealso">
   &reftitle.seealso;
   <para>