## Requirements for Deck/Card Elements

Valid WML elements include the following:

Type of Elements | Element
--- | ---
Deck/card elements | wml, card, template, head, access, meta
Event elements | do, ontimer, onenterforward, onenterbackward, onpick, onevent, postfield
Tasks | go, prev, refresh, noop
Variables | setvar
User input | input, select, option, optgroup, fieldset
Anchors, Images, Timers, Variables | a, anchor, img, setvar, timer

Unsupported tags (not well-formed) cause the error message Page cannot be rendered to appear in the Prompt Line. The error message Page contains invalid tags displays on the Prompt Line if the XML parser fails.

The attributes xml:lang, class, and id are universal attributes associated with every wml element. The Web browser supports these tags as follows:

Attribute | Support | Comments
--- | --- | ---
xml:lang | No - will not be used | Currently only English is supported.
class | No - will not be used | Only half of the phone browsers support this attribute.
id | Yes - will be used |

The three universal tags are not repeated in requirements for other tags.The Summary Of WML Tags and Attributes on page 99 is a complete list of all supported tags and attributes.