HTML and CSS Reference
In-Depth Information
to the head of a document, links in the body that are coded relative to the
current document, such as
<a href="about.html">about</a>
, are resolved as
http://example.net/about.html, and not as from the development server, such
as http://dev.example.net/about.html.
his applies to all relative URLs in the document, including URLs in
image
,
area
, and
object
elements, as well as any
script
and
link
elements in the
document head that appear ater the base element. For this reason, care must
be taken with the placement of a base element. It is usually placed at the end
of the document's head section, and the URLs in any
link
or
script
elements
appearing before it are coded using full URLs, unless they too are under
development.
he
base
element can also be used to change the default targeting of links.
For example, this element:
<base target=" _blank"/>
instructs the browser to open any links in a new window unless the link
(anchor or area element) already has a target attribute with a window name or
one of the other special values:
"_self"
or
"_parent"
.
Avoid the use of
base
elements in production websites. hey make it more
diicult for robots to analyze the site's structure and may hamper the eforts of
other developers to maintain the code. here is usually a better approach using
web server directives, so check with your local webmaster before adding
base
elements to your documents' heads.
It is not an understatement to say that the advent of search has changed the
Web. For any website that wants to attract visitors, getting the attention of
search robots and making it easy for them to index and rank the site is essen-
tial. his is the evolving practice of search engine optimization (SEO). You
may also consider SEO an art, because the essential goal is to please an audi-
ence with interesting concepts and new knowledge. his audience is composed
of search robots and other user agents and, like theatergoers, each brings its
own tastes and prejudices to a performance. Robot tastes are evolving, and you
might be concerned that trying to please all your human and robot visitors is
impossible. Fortunately, the major search engine companies document their
indexing and ranking protocols and provide tools to measure your website's
SEO level.
