Got a source for that? I&#x27;ve taken a quick look and can&#x27;t find anything mentioning these before late 2015. Slack&#x27;s blog post was in July (<a href="http:&#x2F;&#x2F;slackhq.com&#x2F;post&#x2F;123561085920&#x2F;reactions" rel="nofollow">http:&#x2F;&#x2F;slackhq.com&#x2F;post&#x2F;123561085920&#x2F;reactions</a>)