问题
I've seen this in the footer of various websites, most of them non-technical websites. Some websites go even further and include a W3C badge stating the fact. I don't see how this can be of any help to the targeted audience.
回答1:
I can think of a few possible reasons:
It may be a marketing tool. "Look, we code to appropriate standards!" This could apply to the individual who designed the site (and might include it in their portfolio), even if the company as a whole is non-technical.
It could be a means of spreading awareness about XHTML, et al. "You should code to appropriate standards, too!"
It might improve the perception of quality for the site as a whole (and maybe the company's products, by association). I don't really think this is particularly likely, but some marketing departments might.
As others have noted, it could just be a point of pride for the web designer.
回答2:
Honestly, I think it's just done to brag. "Hey, look, my website uses valid XHTML!" It doesn't really serve any purpose other than to show that it was well coded.
回答3:
It's a badge of pride. I don't necessarily think I agree with plastering sites with validation iconography, but I do firmly believe in coding to standards. The web is a much less difficult place to work than it used to be because of the hard work of the W3C et al.
回答4:
In most cases, this badge is a link to an auto-validation task ran against the referring site. This is an invitation for the audience to scrutinize the quality of your work.
回答5:
It doesn't serve any useful purpose. Just because a site is xhtml compliant doesn't mean it is well coded. It just means the developer cares whether or not the site is xhtml compliant or not.
回答6:
It usually means there's some JavaScript behind that adds target attributes on links after the page has loaded.
回答7:
I'd add two more to John Hyland's answer:
- By stating that the page/site is well-formed, it may state that it can be more easily parsed by third-parties.
- For re-usable content (e.g. Creative Commons licensing), it informs that the code may be copy/pasted or included without breaking W3C compliance.
回答8:
I'm fascinated by what people put in the footer. All kinds of junk down there. Sometimes there is even navigation that I wish were at the top of the page. Example:
stackoverflow.com | serverfault.com
回答9:
I've also seen sites with W3C badge who actually do not pass validation.
回答10:
It doesn't, in my opinion many webdesign agencies put it as a sign of quality in the site. Sometimes make a good site XHTML compliant is not an easy task.
回答11:
People generally put a valid at the bottom to display that their website is complaint with the W3C standards for building websites. If a website isn't working correctly and hasn't got a valid link or image at the bottom then its probably been poorly written. By validating your website through the W3C shows that you have correctly coded your pages.
回答12:
The W3C HTML validator and CSS validator contain linking code to display banners that markup and CSS are valid.
It's mainly to tell you that the authors have actually bothered to make sure that the XHTML and CSS are valid.
Unfortunately, being syntax error-free doesn't make it logic-error free.
回答13:
Short answer: You do not NEED it on a web page.
Any reason that it was put there is subjective to the author of the page and does not really concern you.
来源：https://stackoverflow.com/questions/1053916/why-would-you-need-a-valid-xhtml-css-notice-at-the-end-of-a-page