If you have created an XML sitemap for your website add the following line to your robots.txt file for each sitemap:
These tags for the sitemap xml file are an optional extra you can use to help streamline the indexing of pages in your website.
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url>
<loc>http://www.yourwebsite.com.au</loc>
<product:title>![CDATA[Website Page Title]]</product:title>
<product:description>![CDATA[Product Description]]</product:description>
<product:image:url>http://www.yourwebsite.com.au/images/product_image1.png</product:image:url>
</url>
<url>
<loc>http://www.yourwebsite.com.au/products</loc>
<product:title>![CDATA[Website Page Title]]</product:title>
<product:description>![CDATA[Product Description]]</product:description>
<product:image:url>http://www.yourwebsite.com.au/images/product_image1.png</product:image:url>
</url>
</urlset>
<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>http://www.yourwebsite.com.au/sitemap1.xml</loc>
</sitemap>
<sitemap>
<loc>http://www.yourwebsite.com.au/sitemap2.xml</loc>
</sitemap>
</sitemapindex>