A unique hashtag is a special keyword or phrase that helps identify and organize specific content on social media. It distinguishes itself from other hashtags by being different and not used by other people or for different purposes. Full definition
Both the Red Sox and Cardinals have created unique hashtags on Twitter to engage their followers. (epolitics.com)
This includes «liking» pages which is the most lucrative at 250 points per property and also sharing social media content, checking in at specific properties and using unique hashtags (e.g., #LoveMarriottRewards) for 25 points each. (leapforwardtravel.com)
Limit the chat to one hour, and remind the host to create a unique hashtag to make it easy for people to find. (entrepreneur.com)