_scoreTag allows you to tag your posts the same way you could using twitter #hashTags

It is has a _chromeExtension which turns a _scoreTag into a link. This allows users to quickly find other posts regarding a particular topic.

Why not just use #hashTag? Well, google ignores the # symbol when it indexes pages for searching, so it doesn't do much good if you actually want to find posts using it.

Google+ _scoreTag - Chrome Web Store

https://chrome.google.com/webstore/detail/cjllnhndndjlchndmfoalkodbpdlmedb