Pages should be tested with as many browsers as possible, particularly
if you are using HTML extensions specific to a particular browser such
as Netscape or Microsoft Internet Explorer. Browsers which don't understand
particular tags are supposed to ignore them. However, they occasionally
behave unpredictably. Also, some browsers are more lenient than others
about HTML syntax which is not strictly compliant to standards.
Elements to be particularly careful of when testing include image maps,
browser will behave differently on different platforms. For example, a
particular feature may work fine on the PC version of a browser, but not
on the Unix implementation. This is because often separate development
teams work on each platform, releasing their own versions incorporating
new features at different times and, potentially, with different bugs.
It is important to keep in mind that not all World Wide Web browsers
support graphics. Some, such as lynx, can run on terminals such as the
VT100, and offer the advantage of much faster performance in low
network bandwidth conditions.
Therefore, it is necessary to assign a word or phrase to replace each
image when it cannot be displayed. This can be done using the
ALT modifier tag. If you do not want anything to appear
in place of the image, then define the tag to be ALT="".
Otherwise, the default tag "[Image]" will be assigned. These tags have
been defined for the images linked to this document. See the source
html page for an example. ALT tags are now required for ALL images to
conform to section 508, a Federal law. Read more about ALT tags.
HEASARC Home |
Last modified: Monday, 19-Jun-2006 11:24:57 EDT
The HEASARC welcomes your participation in a brief survey to capture how users access and utilize HEASARC data, software, and services. The outcome(s) of this survey will be used to guide, prioritize, and plan our activities and development in the coming years. It contains 18 questions, generally takes just a few minutes to complete, and your answers will remain totally anonymous. We thank you in advance for your valuable feedback.