If you are not aware of XHTML, related standards, and whether XHTML output is an important feature for your web site, please refer to the following pages:
Our ASP.NET products render HTML code that complies to the XHTML 1.0 Transitional specification. Presently, this is the most widely accepted spec and the default document type for web pages created with Visual Studio® 2005 and Visual Studio® 2008.
We do our best to render 100% XHTML compliant code in all possible control usage scenarios, but there are a few instances when it is simply impossible to do so. These instances fall into two main categories, i.e. two main reasons to render incompliant code. The first reason is cross-browser compatibility support. Certain browsers don't fully support valid XHTML markup. The second reason is to provide advanced features that can't be implemented with valid XHTML code. In such instances, you can choose between having valid code or using the required feature.
All XHTML compliance issues, with appropriate reasoning, are listed below.
ASPxObjectContainer Component
Under certain circumstances, the ASPxObjectContainer component renders the <embed> tag, which is invalid according to the XHTML specification. This tag is required for cross-browser compatibility, since the <object> tag, which is a valid replacement for the <embed> tag, is not correctly processed by some browsers, including Mozilla FireFox.
The <embed> tag is rendered if the control's content is:
- A video or audio file.
- A flash animation (if the component's ObjectProperties.EmbedMethod property is set to TwiceCooked).
Image Alignment Attributes
Some of our ASP.NET controls expose properties specifying alignment for embedded images. These properties are of ImageAlign type, which is an enumeration. Though this is a standard ASP.NET enumeration, some of its values are invalid based upon the XHTML specification. Invalid values include: AbsBottom, AbsMiddle, Baseline and TextTop.