Excerpt from the W3C Recommendations for HTML 4

http://www.w3.org/TR/REC-html40/struct/objects.html#h-13.1                                      edit P.Komisar


Following is the section of the Recommendation pertaining to the Applet Tag specifically.

13.4 Including an applet: the APPLET element

APPLET is deprecated (with all its attributes) in favor of OBJECT.

See the Transitional DTD for the formal definition.

Attribute definitions

         codebase = uri [CT]
              This attribute specifies the base URI for the applet. If this attribute is not specified, then it
              defaults the same base URI as for the current document. Values for this attribute may only
              refer to subdirectories of the directory containing the current document. Note. While the
              restriction on subdirectories is a departure from common practice and the HTML 3.2
              specification, the HTML Working Group has chosen to leave the restriction in this version
              of the specification for security reasons.
         code = cdata [CS]
              This attribute specifies either the name of the class file that contains the applet's compiled
              applet subclass or the path to get the class, including the class file itself. It is interpreted with
              respect to the applet's codebase. One of code or object must be present.
          name = cdata [CS]
              This attribute specifies a name for the applet instance, which makes it possible for applets
              on the same page to find (and communicate with) each other.
          archive = uri-list [CT]
              This attribute specifies a comma-separated list of URIs for archives containing classes and
              other resources that will be "preloaded". The classes are loaded using an instance of an
              AppletClassLoader with the given codebase. Relative URIs for archives are interpreted with
              respect to the applet's codebase. Preloading resources can significantly improve the
              performance of applets.
          object = cdata [CS]
              This attribute names a resource containing a serialized representation of an applet's state. It
              is interpreted relative to the applet's codebase. The serialized data contains the applet's
              class name but not the implementation. The class name is used to retrieve the
              implementation from a class file or archive.

              When the applet is "deserialized" the start( ) method is invoked but not the init( ) method.
              Attributes valid when the original object was serialized are not restored. Any attributes
              passed to this APPLET instance will be available to the applet. Authors should use this feature
              with extreme caution. An applet should be stopped before it is serialized.

              Either code or object must be present. If both code and object are given, it is an error if they
              provide different class names.

         width = length [CI]
              This attribute specifies the initial width of the applet's display area (excluding any windows or
              dialogs that the applet creates).
         height = length [CI]
              This attribute specifies the initial height of the applet's display area (excluding any windows
              or dialogs that the applet creates).

Attributes defined elsewhere

            id, class (document-wide identifiers)
            title (element title)
            style (inline style information)
            alt (alternate text)
            align, hspace, vspace (visual presentation of objects, images, and applets)

This element, supported by all Java-enabled browsers, allows designers to embed a Java applet
in an HTML document. It has been deprecated in favor of the OBJECT element.

The content of the APPLET acts as alternate information for user agents that don't support this
element or are currently configured not to support applets. User agents must ignore the content
otherwise.

DEPRECATED EXAMPLE
 
Example 1

// In the following example, the APPLET element includes a Java applet in the document.
//  Since no codebase is supplied, the applet is assumed to be in the same directory as the 
// current document.

            <APPLET code="Bubbles.class" width="500" height="500">
                               Java applet that draws animated bubbles.
                                                                                                            </APPLET>
  // This example may be rewritten with OBJECT as follows:

          <OBJECT codetype="application/java"
                            classid="java:Bubbles.class"
                             width="500" height="500">
                            Java applet that draws animated bubbles.
                                                                                                            </OBJECT>
.

 Example 2

           // The following sample Java applet:

            <APPLET code="AudioItem" width="15" height="15">
                <PARAM name="snd" value="Hello.au|Welcome.au">
                   Java applet that plays a welcoming sound.
                                                                                             </APPLET>
          // may be rewritten as follows with OBJECT:

            <OBJECT codetype="application/java"
                  classid="AudioItem"  width="15" height="15">
               <PARAM name="snd" value="Hello.au|Welcome.au">
                 Java applet that plays a welcoming sound.
                                                                                              </OBJECT>
.