1. Login to your Google Webmaster. Go to Diagnostics > HTML suggestions . Under Title tag > Duplicate title tags. At here, you can see if your website got pages with the duplicate title tags.
2. From above picture, you can see that this website got issue with the duplicate title tags. This duplicate title tags is caused when Google Webmaster thinks that there are another pages existed with the same title tag and meta description.
3. In order to fix this, you need to go to Site configuration > Settings > Parameter handling. Look for parameter replytocom and set to Ignore under Action.
4. Additional to that, you can also block the Google Bot agent from crawling to your website. Open your robots.txt file and add the following:
User-agent: * Disallow: /cgi-bin/ Disallow: /wp-admin/ Disallow: /wp-includes/ Disallow: /wp-content/plugins/ Disallow: /wp-content/themes/ Disallow: /trackback Disallow: /comments Disallow: /feed User-agent: Googlebot Disallow: /*/trackback Disallow: /*/feed Disallow: /*/comments Disallow: /*?* Disallow: /*? Disallow: /*page/* Disallow: /category Disallow: /category/*/* Disallow: */trackback Disallow: *?replytocom
