Twitter is adding yet another public metric to measure posts by. There’s now a counter for how many bookmarks a tweet has gotten that lives beside the retweet, quote retweet, and like numbers. The counter is currently only showing up for iOS users who visit the tweet details page, but a help document says there are “plans to expand.”

Unlike other metrics, you can’t tap the bookmarks counter to see who’s added it to their list. According to the Twitter Support account, “bookmarks are still private” and the company will “never display which accounts have added a Tweet to their Bookmarks.”