Antony wrote:Designing webpages using some browser specified tags or extensions is
encouraged. The feature is there, as long as visitors of other browsers
do not get blocked or unable to display the content at all.
e.g.

No. The use of any non-standard code that is designed to work only in specific browsers and is
non-compliant to W3C recommendations must be
strongly discouraged, in favour of
recommended standard code that works well in ALL browsers.
Using browser specific code can cause websites to appear broken in other browsers, and is an
unwelcome kickback to around 1995-1999, when Netscape and Microsoft were both as bad
as each other, for coming up with non-standard tags that would only work in their own
browsers, and appear broken (if they appeared at all) in the rival product.
And your screengrab seems only to demonstrate how certain types of webpage coding
affect browsers made for Mac OS X. Since that's only a small percentage overall, it
makes that screengrab a rather inconclusive part of the argument.
Websites should comply with W3C guidelines, not Apple Human Interface Guidelines!
And we don't want to create websites to be viewed on Apple Macs only, now do we?
And while I'm currently only able to use a Mac at moment, any webpages I create
with it, will adhere to the recommended web standards as close as possible, so
that I can be sure they'll be displayed with little or no inconsistencies, on
any current or recent browser . . . and that even includes IE . . . !
UserAgent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8b4) Gecko/20050910 SeaMonkey/1.0a
SeaMonkey = Swiss Army Knife: It's versatile, reliable, and contains useful tools.
Windows Internet Explorer = Old Swiss Cheese: Full of holes, and it stinks!