<A> ... Level 0
An anchor is a marked section of text that is the start and/or destination of a hypertext link. Anchor elements are defined by the `<A>' tag. The `<A>' tag accepts several attributes; at least one of the NAME and HREF attributes is required.
Attributes of the `<A>' tag:
If the HREF attribute is present, the text between the opening and closing anchor tags becomes hypertext. If this hypertext is selected by readers, they are moved to another document, or to a different location in the current document, whose network address is defined by the value of the HREF attribute.
Example:
See HaL's information for more details.
In this example, selecting "HaL" takes the reader to a document at http://www.hal.com. The format of the network address is specified in the URI specification for print readers.
With the HREF attribute, the form HREF="#identifier" can refer to another anchor in the same document.
Example:
The glossary defines terms used in this document.
In this example, selecting "glossary" takes the reader to another anchor (i.e., Glossary) in the same document. The NAME attribute is described below. If the anchor is in another document, the HREF attribute may be relative to the document's address or the specified base address (see section Base).
If present, the NAME attribute allows the anchor to be the target of a link. The value of the NAME attribute is an identifier for the anchor. Identifiers are arbitrary strings but must be unique within the HTML document.
Example of use:
Coffee is an example of ... ... An example of this is coffee.
Another document can then make a reference explicitly to this anchor by putting the identifier after the address, separated by a hash sign:
The TITLE attribute is informational only. If present, the TITLE attribute should provide the title of the document whose address is given by the HREF attribute. The TITLE attribute is useful for at least two reasons. The HTML interpreter may display the title of the document prior to retrieving it, for example, as a margin note or on a small box while the mouse is over the anchor, or while the document is being loaded. Another reason is that documents that are not marked up text, such as graphics, plain text and Gopher menus, do not have titles. The TITLE attribute can be used to provide a title to such documents. When using the TITLE attribute, the title should be valid and unique for the destination document.
The REL attribute gives the relationship(s) described by the hypertext link from the anchor to the target. The value is a whitespace-separated list of relationship names. Relationship names and their semantics will be registered by the W3 Consortium. The default relationship is void. The REL attribute is only used when the HREF attribute is present.
The REV attribute is the same as the REL attribute, but the semantics of the link type are in the reverse direction. A link from A to B with REL="X" expresses the same relationship as a link from B to A with REV="X". An anchor may have both REL and REV attributes.
If present, the URN attribute specifies a uniform resource name (URN) for a target document. The format of URNs is under discussion (1995) by various working groups of the Internet Engineering Task Force.
The METHODS attributes of anchors and links provide information about the functions that the user may perform on an object. These are more accurately given by the HTTP protocol when it is used, but it may, for similar reasons as for the TITLE attribute, be useful to include the information in advance in the link. For example, the HTML interpreter may chose a different rendering as a function of the methods allowed; for example, something that is searchable may get a different icon.
The value of the METHODS attribute is a whitespace-separated list of HTTP methods supported by the object for public use.