HTML and CSS Reference
browser can determine the object type from the object's URL or server.
You must supply a type attribute if you don't include the src attribute.
It may seem odd to use an <embed> tag without an src attribute reference
to some object, but this is common if the plug-in requires no data or
retrieves its data dynamically after it is started. In these cases, the type
attribute is required so that the browser knows which plug-in to invoke.
22.214.171.124. The units attribute
Pixels are the default unit of measure for the height and width attributes
that control the <embed> display space. The units attribute lets you expli-
citly state that the absolute measure is pixels , or change it to the relat-
ive en , which is one-half the current point size of text in the document.
With the en units, you tailor the object's viewing area ( viewport ) to be
proportional to its immediately surrounding content, the size of which is
varied by the user.
For example, this tag creates a viewport of 200 x 320 pixels:
<embed src=movie.avi height=200 width=320 units=pixels>
By changing units to en , that same viewport, when included within a
flow of 12-point text, becomes 1200 x 1920 pixels.
12.2.5. The <noembed> Tag (Extension)
The <noembed> tag, although not part of the standards, is supported by
the popular browsers; they consequently ignore the <noembed> enclosed
text. On the other hand, browsers that do not recognize <embed> ignore
<noembed> , too, consequently displaying the latter tag's enclosed text
and thereby supplying alternative content to tell users what they are
missing in the <embed> content.