go spec: note re: append() not being implemented yet

R=rsc
CC=golang-dev
https://golang.org/cl/2761041
diff --git a/doc/go_spec.html b/doc/go_spec.html
index 3aaa256..835f9dd 100644
--- a/doc/go_spec.html
+++ b/doc/go_spec.html
@@ -1,5 +1,5 @@
 <!-- title The Go Programming Language Specification -->
-<!-- subtitle Version of Oct 25, 2010 -->
+<!-- subtitle Version of Oct 26, 2010 -->
 
 <!--
 TODO
@@ -4558,6 +4558,10 @@
 </pre>
 
 <p>
+<span class="alert">Note: <code>append</code> is not yet implemented.</span>
+</p>
+
+<p>
 The function <code>copy</code> copies slice elements from
 a source <code>src</code> to a destination <code>dst</code> and returns the
 number of elements copied. Source and destination may overlap.
@@ -5228,6 +5232,7 @@
 <h2 id="Implementation_differences"><span class="alert">Implementation differences - TODO</span></h2>
 <ul>
 	<li><span class="alert">Implementation does not honor the restriction on goto statements and targets (no intervening declarations).</span></li>
+	<li><span class="alert">The <code>append</code> built-in function is not yet implemented.</span></li>
 	<li><span class="alert">Gccgo: Method expressions are partially implemented.</span></li>
 	<li><span class="alert">Gccgo: allows only one init() function per source file.</span></li>
 </ul>