'a is known as a phantom type. The implementation is
actually monomorphic (the different element types are distinguished
by a homogeneous variable, such as their textual representation)
and the type variable
`a is just used by the type checker.
NB: It might be possible to use polymorphic variants directly, without phantom types, but the implementation is likely to be more involved.
Values of the title attribute may be rendered by user agents in a variety of ways. For instance, visual browsers frequently display the title as a tool tip (a short message that appears when the pointing device pauses over an object). Audio user agents may speak the title information in a similar context.
The title attribute has an additional role when used with the
element to designate an external style sheet. Please consult the
section on links and style sheets for details.
This attribute is used to describe a reverse link from the anchor specified by the href attribute to the current document. The value of this attribute is a space-separated list of link types.
This attribute gives an advisory hint as to the content type of the content available at the link target address. It allows user agents to opt to use a fallback mechanism rather than fetch the content if they are advised that they will get content in a content type they do not support.Authors who use this attribute take responsibility to manage the risk that it may become inconsistent with the content available at the link target address.
This attribute specifies the visible width in average character widths. Users should be able to enter longer lines than this, so user agents should provide some means to scroll through the contents of the control when the contents extend beyond the visible area. User agents may wrap visible text lines to keep long lines visible without the need for scrolling.
This attribute specifies the number of visible text lines. Users should be able to enter more lines than this, so user agents should provide some means to scroll through the contents of the control when the contents extend beyond the visible area.
Label authorizes only one control inside them
that should be labelled with a
(although it is not necessary). Such constraints are not currently
enforced by the type-system
Unsafe features. Warning using this module can break HTML5 validity and may introduce security problems like code injection. Use it with care.