Hashtags can be indexed and displayed in your group tweets by first following @hashtags. The service will follow you back automatically.

Second step is to get familiar with hashtag commands, so that you only broadcast a message out to the people you want to receive it, those being the members of your hashtag group.

* Follow #tag – (example: follow #tcot) – lets you follow all updates tagged with #tcot. 

* Follow username#tag – subscribe to all updates from a certain person that are sent to a group. (Example: Follow jeffselig#tcot will give you every post by Jeff sent to the #tcot group)

* #tag message – Send a message or question to the group. (Example: #tcot Anyone know a great software program to organize tweets?)

* #tag !message – Send a message only to people who are subscribed to updates from #tag. (Example: #twitip !How many tcot users post to twitter daily?) 

* Leave #tag – Unsubscribe from the group. If your friends are subscribed to this group as well, you’ll still get messages from them that include updates for the group. (Example: leave #food will unsubscribe you from the Food group, but you’ll still get messages from your best friend and fabulous cook Jenny whenever she sends a message to #food).

* Remove #tag Unsubscribe from the group and from friend messages that include this tag. So if Jenny posts a recipe to #food and you’ve typed Remove #food in your Twitter status bar, you won’t see that recipe even if Jenny is on your followers list.