Currently I use Meta Robot tags and not a robot.txt file. I wanted to add a robot.txt to include the new Sitemap parameter: Sitemap: http://www.example.com/sitemap.xml Because I current already use Meta Robot tags and just want to add the new sitemap paramater do I need include anything for in my robot.txt file than: Sitemap: http://www.example.com/sitemap.xml
No, it's not required. If you feel more comfortable you can add User-agent: * Disallow: HTML: that will tell to all spiders to go ahead and index your site.
It may help to read the actual question before answering. Your answer is wrong by the way. You can put a robots.txt file with just the sitemap line in it. It shuld not affect your indexing in any way. If unsure, the recommendation from weppos is valid.