The "pound" key on your keyboard (#) is called an octotroph. Nowadays users create and use hashtags by placing this sign (which is also called a hash character or number sign) in front of a word or unspaced phrase, either in the main text of a message or at the end. A hashtag is a type of label or metadata tag used on social network and microblogging services which makes it easier for users to find messages with a specific theme or content. Searching for that hashtag will then present each message that has been tagged with it. For example, on the photo-sharing service Instagram the hashtag #bluesky allows users to find images that have been tagged as containing the sky. Hashtags can be used to collect public opinion on events and ideas at the local, corporate, or world level. For example, searching Twitter for #worldcup2014 returns many tweets from individuals around the globe about the 2014 FIFA World Cup.