A Web feed, also referred to as a syndication feed, is a popular format for providing users with frequently updated data and content. They can be used across a network of websites for products, news or blogs. Users, often blog readers, can subscribe to content and receive updated notifications with feeds. The most common delivery formats are RSS and XML. (See also RSS Feed). The aggregation of a web feed is the act of making a collection of web feeds available on one page. SEO considerations around web feeds including maintaining the ownership of content once it is syndicated (see also Duplicate Content).