Differences Between HTML and XHTML NONE Tips and Notes Tip: To deal with browsers that do not understand iframes, place the text you want between the opening _ tag and the closing tag. Optional Attributes DTD indicates in which HTML 4.01/XHTML 1.0 DTD the attribute is allowed. S=Strict, T=Transitional, and F=Frameset. Attribute Value Description DTD align left right top middle bottom Deprecated. Use styles instead. Specifies the alignment of an iframe according to surrounding elements TF frameborder 1 0 Specifies whether or not to display a border around an iframe TF height pixels % Specifies the height of an iframe TF longdesc URL Specifies a page that contains a long description of the content of an iframe TF marginheight pixels Specifies the top and bottom margins of an iframe TF marginwidth pixels Specifies the left and right margins of an iframe TF name name Specifies the name of an iframe TF scrolling yes no auto Specifies whether or not to display scrollbars in an iframe TF src URL Specifies the URL of the document to show in an iframe TF width pixels % Specifies the width of an iframe TF Standard Attributes The _ tag supports the following standard attributes: Attribute Value Description DTD class classname Specifies a classname for an element TF id id Specifies a unique id for an element TF style style_definition Specifies an inline style for an element TF title text Specifies extra information about an element TF