clarification on laptop to bring

We sometimes get questions about what OS people should use. We also see often people coming with laptops that they don't have admin rights on.
Do we want to go ever further and say a recent version of the OS?  We may have some challenges if people come with,  say, Windows XP or Ubuntu   10.4 (or whatever Mac's outdated version is -- I've never used a Mac).

index.html

@@ -113,8 +113,9 @@ <h2 id="general">General Information</h2>
   Modify the block below if there are any special requirements.
 -->
 <p id="requirements">
-  <strong>Requirements:</strong> Participants must bring a laptop with
-  a few specific software packages installed (listed
+  <strong>Requirements:</strong> Participants must bring a laptop with a 
+  Mac, Linux, or Windows operating sytem (not a tablet, Chromebook, etc.) that they have administrative privileges
+  on. They should have a few specific software packages installed (listed
   <a href="#setup">below</a>). They are also required to abide by
   Software Carpentry's
   <a href="{{site.swc_site}}/conduct.html">Code of Conduct</a>.