When developing a public facing website using the publishing features of MOSS it might be required to emit a ROBOTS meta tag that prevents internet search engines from indexing specific pages.

The standard RobotsMetaTag control included in WSS generates the following tag:

<META NAME="ROBOTS" CONTENT="NOHTMLINDEX">

Unfortunatelly most search engines do not understand the NOHTMLINDEX content value but a value of NOINDEX. To resolve this it is required to replace the RobotsMetaTag control in the master page with a custom control that emits the correct value.

The following code will do this:

Here are the required steps to implement this:

1. compile the above code into a separate DLL (e.g. RobotsMetaTag.dll)
2. if signed add the DLL to the GAC - otherwise copy it into the bin directory of your web application
3. add the control to the save controls list in the web.config
   
         <SafeControl Assembly="RobotsMetaTag" Namespace="StefanG.MossControls" TypeName="*" Safe="True" />
   
   (if the DLL is in the GAC ensure to add the strong assembly name instead with version and public key token).
4. Open the master page in SharePoint designer and register your DLL:
   
         <%@ Register TagPrefix="StefanG" Namespace="StefanG.MossControls" Assembly="RobotsMetaTag" %>
   
   (if the DLL is in the GAC ensure to add the strong assembly name instead with version and public key token).
5. replace the following tag:
   
         <SharePoint:RobotsMetaTag runat="server"/>
   
   with this:
   
         <StefanG:RobotsMetaTag runat="server"/>