Finally, a mechanism for sharing files on twitter that works WITHIN twitter itself. No more third-party services and cryptic short URLs, now you can share files directly with your friends or with the world one tweet at a time.One header for the file transfer. This contains the string “==BEGIN”, the file name, file permissions, and a modified Base64-encoded string of the file's MD5 checksum with the hashtag “#tweetftp” on the end. We modify the string to remove the trailing = signs and replace the characters '+' and '/' with '-' and '_' respectively. While clients may use the checksum to verify the file was retrieved correctly, this is not a requirement: the checksum is primarily used to associate the status updates with one another. The header is also where clients may add a few hashtags to describe the file.