Web browser developers created different modes for the browsers to operate in order to allow Web browsers to be backwards compatible with Web pages built for older Web browsers. These modes are defined by the presence or absence of a DOCTYPE. The <!DOCTYPE> declaration is the very first item in the document, before the <html> tag. This tag tells the browser which HTML or XHTML specification the document uses.
A new DOCTYPE field is present on the Blackbaud NetCommunity 5.0 Layout Properties screen. In this field, you can select whether to use XHTML 1.0 Transitional (DOCTYPE) code on your website's layout. Blackbaud NetCommunity has moved forward with standards compliancy by allowing you to implement a DOCTYPE (XHTML 1.0 Transitional).
Blackbaud NetCommunity has moved forward with standards compliancy by enabling you to implement a DOCTYPE (XHTML 1.0 Transitional). When you use a DOCTYPE, browsers render the HTML and CSS related to the chosen layout in the standards of the World Wide Consortium (W3C) linked to it. Because a DOCTYPE changes how browsers render Web pages, design differences may occur on your existing website. Therefore, Blackbaud does not recommend implementing a DOCTYPE until you completely understand how it affects your existing website.