"A hashtag is a word or a phrase prefixed with the symbol # ... Hashtags provide a means of grouping such messages, since one can search for the hashtag and get the set of messages that contain it." (from Wikipedia)
Hashtags are extensively used on social networks, but they could be helpful for your business, too. Imagine to keep in copy your Deal Flow Management System while writing an e-mail related to to a specific activity you've done you just want to send to your team: by including a specific hashtag as your deal's identifyer, your system will parse it and will add it to the activity log of the deal.
inPrivate Deal Flow Updates your deals by parsing your e-mails and seeking hashtags
inPrivate has now this hastag parsing feature for inbound e-mails: try it by subscribing for a free Trial here.