You can use a hashtag (#) in a message to call out a meaningful term or topic, making it easy to find all content associated with that term or topic. For example, imagine discounts is a popular topic in your group, but the discounts can come in the form of dealer incentives, cash-back deals, seasonal discounts, or any other number of forms. How do you find what everyone is saying about all those things? You use a hashtag. Every time you or your colleagues say something about some form of discount, you include the hashtag #discounts.
You can then click a #discounts hashtag link to view a list of all messages in otherwise unrelated Conversations and walls that contain the hashtagged term.
Adding Hashtags
You can add one or more hashtags to any message (comments, replies, annotations, and document messages) simply by typing "#" before a term. When you start typing a hashtag by typing "#" plus at least one letter, existing hashtags (ones that have been used before) appear for you to select from.
Tips:
You can include the following characters in a hashtag: A through Z, a through z, 0 through 9 and _.
A hashtag can be a maximum of 25 characters (not including the "#").
Searching for and Viewing Hashtags
When you perform a search, available hashtags are included in the results. You can limit your search results to hashtagged messages by starting your search term with a hashtag (#).
Wherever you see them, hashtagged terms are clickable and will open a hashtag page where all messages that include that hashtag are shown. So clicking #discounts in any Conversation opens a #discounts page which shows any message (in a Conversation, document annotation, wall, or such) that you have access to that includes the discounts hashtag.
On the hashtag page, you can filter the messages to show all messages that include the hashtag (All Results) or just those messages posted by people you are following (By People You Follow).
Following Hashtags
You can also follow hashtags. When you follow a hashtag, messages in public Conversations and walls that contain that hashtag appear in recent activities (from the navigation menu on the left, select Overview), even if you are not a member of those Conversations or walls.
To follow a hashtag, click the hashtag to open the hashtag page, then click Follow at the top of the page. To stop following the hashtag, click Unfollow.