Fb:if-multiple-actors
From Facebook Developer Wiki
Description
Displays the enclosed content when more than one actor is involved in a Feed story. Use this tag in the templates you create with the Feed Template Console or the feed.registerTemplateBundle method.
If two or more stories are aggregated, then the {actor} token is replaced with the names of all of the users whose actions are being aggregated.
Examples
{actor} <fb:if-multiple-actors>are<fb:else>is</fb:else></fb:if-multiple-actors> testing feed stories.
