Facebook is introducing hashtags, the number signs used on Twitter, Instagram and other services to identify topics being discussed and allow users to search for them.

Facebook Inc. said in a blog post Wednesday that users will be able to click a hashtag to see a feed of discussions about a particular topic. For example, typing a number sign in front of "ladygaga" or "sunset" will turn the words into a link that users can click on to find posts about Lady Gaga or sunsets.

Facebook said hashtags are a first step toward making it easier for users to find out what others are discussing.

If Twitter's use of hashtags is any indication, Facebook will likely incorporate them into its advertising business.

- Associated Press