Elements, which belong only to the Forms Module are BUTTON, FIELDSET, LEGEND and OPTGROUP.

Elements, which belongs also to the Basic Forms Module are FORM, INPUT, LABEL, SELECT, OPTION and TEXTAREA.

The FIELDSET element is also in WML and at least it is useful to classify form elements into logical groups.

This element is supported in MS IE 4.0b2+, Opera 4.x+, Netscape 6.x+ and other as new Mozilla Gecko browsers. Note, that Opera doesn't render any visible borders to this element without CSS.

They are handled in FIELDSET (also the element TABLE has two different modules). The attribute target can be used in XHTML 1.1 by adding the Target Module. Attributes onreset and onsubmit belong to event handlers of scripting languages. They belong in the Modularization of XHTML to the Intrinsic Events Module.

The element FORM supports use the usage of the attribute name, but in XHTML it needs also the attribute id at the same value.

It doesn't belong then either to XHTML 1.1. This element in not recommended to be used anymore. Authors should use instead the INPUT or some other widely supported form element.

This element seems not be supported in MS IE 5.5 and some build of Mozilla don't support it, but it is supported in new Mozilla Gecko browsers, for example in Mozilla 0.7+ (look at the model, where I have used this element).

The transitional attribute align needs in XHTML 1.1 the Legacy Module. Attributes onblur and onfocus etc. belong to event handlers of scripting languages. They belong in the Modularization of XHTML to the in Intrinsic Events Module.

INPUT is wide supported, but BUTTON is supported only in MS IE 4.0b2+, Mozilla Gecko and partially in Opera 4.x+ browsers (full support came mostly in Opera 5.x). Opera 5.x added support for disabled and readonly attributes on the form elements, but Opera gets it wrong and submits disabled elements even if should not to do them still (this is presumably fixed in newest versions but I have not tested).

Forms have also a proprietary element KEYGEN, which is supported by Netscape 3.x+ (not in Mozilla Gecko browsers) and Opera 3.x+. The usage resembles the hidden INPUT element. Netscape informs also about INLINEINPUT element. Some elements, which Netscape inform might not be supported.

The transitional attribute align needs in XHTML 1.1 the Legacy Module. Attributes onblur and onfocus etc. belong to event handlers of scripting languages. They belong in the Modularization of XHTML to the in Intrinsic Events Module.

They are fully supported in Mozilla Gecko and Opera 7.x and partially in MS IE 4.0b2+ and Opera 4.x (Opera Software doesn't promise to support them in 4.x). Opera 4.x-6.x has a little bit bad implementation to the LEGEND element and the HTML-functionality to the element LABEL doesn't work like it doesn't work in MS IE (the element doesn't increase the active area around the INPUT element).

Attributes onblur and onfocus etc. belong to event handlers of scripting languages. They belong in the Modularization of XHTML to the in Intrinsic Events Module.

OPTION is widely supported, but OPTGROUP is supported only in Mozilla Gecko browsers, (at least in some level) MS IE 6.0 for Windows and Opera 7.x. On the base of the information of Opera Software, Opera doesn't support event attributes for them. OPTGROUP could be useful in WML - XHTML transformations. Both in (X)HTML and WML the meaning of this element is to create multilevel option choices instead of using just the OPTION element.

Attributes onblur and onfocus etc. belong to event handlers of scripting languages. They belong in the Modularization of XHTML to the in Intrinsic Events Module.

MS IE and Netscape have different default wrap value except in the Netcape 6.0 the wrap is the same (soft; it was before nowrap; I don't know if this has been changed in newest versions). In principle this can be defined with CSS, but it doesn't work in most browsers. The proprietary attribute is in this case better.

These elements were not in the first Dan Connolly's DTD for HTML from 1992 but they are used before the official HTML 2.0 DTD.

None of them is supported in Mozilla 0.6 (the base of Netscape 6.0), but XMP and PLAINTEXT were supported in some daily builds (I don't have tested if this has been changed in newest builds). The main problem is that they are not supported at the same way (read some information from explanations to the DTD-macro %literal;). I put them into an own group even if LISTING and XMP behaves like block elements and with them can partially speak about parent models. Because they don't have any content model, they create an exceptional group.