Producing and maintaining websites requires a wide range of expertise and disciplines, including web design. Web graphic design, interface design, authoring (covering both proprietary and standardized code), user experience design, and search engine optimization are among the various subfields of web design. Though some designers will work on every aspect of the design process, most people will typically work in teams covering different facets of it. Writing markup and other aspects of the front-end (client side) design of a website are included in the design process that is commonly referred to as web design. Within web development, web design and web engineering share some similarities. It is expected of web designers to be aware of usability and, if they create markup as part of their work, to stay current with web accessibility guidelines.