What does this really mean?
Well, this means that I have followed very strict rules on how html should be written for a website according to W3C, which is an international community that develops standards to ensure the long-term growth of the Web.
And what good is that?
Well, this means that my website will look very similar (if not identical) across different types of web browsers and that I haven't mis-used any html in a way that certain browsers, which follow W3C standards, does not understand.
It is not really a big deal to violate the W3C standards since most browsers are smart enough to understand or ignore the mis-use of html but me being a web application architect for a consulting company cannot allow any errors in the html code that I write.
If you click on that image on the footer of any pages in this site, you should see a Passed result without any errors from the W3C Validation Service.
Last night, I incorporated Amazon ads in my website and I could not believe how many errors it introduced on my website. Although it looked fine without any issue on the browser, W3C Validator indicated that there are over 50 errors/violations on my web page as a result of adding amazon ads. Unbelievable....
I ended up spending hours to clean up the Amazon's ad code because I would be too embarrassed to put that image on my website with those violations.
All of my web pages are written in XHTML format. XHTML is very similar to HTML 4.01 standard except that it is much more strict on properly closing the tags in the correct orders, similar to XML conformation. If you want to know more details on how XHTML is different from HTML, check out http://www.w3schools.com/XHTML/xhtml_html.asp
It was not easy for me to adjust and conform to XHTML rules and I still forget or make mistakes time to time. Here is the most common mistakes that people, including myself, make on XHTML document (some of the rules are derived from HTML 4.01 rules):
<br>should be properly closed as
- stand-alone attributes should always have value. <td nowrap> should be
<td nowrap="nowrap">and same goes for selected, checked, and readonly stand-alone attributes.
- "alt" attribute is rerquired for
<img>tag and should also be properly closed.
<img src="picutre.jpg">should be
<img src="picture.jpg" alt="" />
<input>elements should be properly closed as well.
<input type="text" name="email">should be
<input type="text" name="email"/>
<form>tag should be outside of
<table>tag, not inside the table.
- missing "type" attribute for
- missing "" for attribute value, e.g
&ampshould be used instead of
&, including the parameters in a URL
- all tag and attribute names must be in all lower-cases.
onMouseOverare not valid tag/attribute names.
"absmiddle"is no longer a valid for
- No more background attribute for
If your browser doesn't have HTML validation tool, go to http://validator.w3.org and enter the address of your website or any specific pages or even the websites that you know of. If it has less than 5 errors then that's really an impressive website!