Adds extra values to the <b>tags</b> ad-targeting key when a given tag is already present on the page. One rule per line, in the form <code>tag = extra1, extra2</code>. Lines beginning with # are ignored.<br /><br />Tags are matched after normalisation, so <code>Big Mountain</code> and <code>big-mountain</code> are the same rule. Leave this empty unless your ad operations team has asked for specific tags &mdash; extra values only have an effect if matching line items exist in the ad server.