Lucas Matney, TechCrunch:

Twitter is testing a new tag that will make it easier to parse who started a thread. The new feature, which is starting to pop up for some users, makes it easier to find posts from the original tweeter within a thread, but may also help curb (some types of) abuse on the platform, making it easier to distinguish accounts that are masquerading as other tweeters, for instance.

Follow the link, scroll through the pictures to get a sense of how this will work.

I do like the concept, but wonder if this wouldn’t be kinder on screen real-estate if they used an icon, or a special character, or even formatting (bold, for example) to make the original poster stand out.