Sample page using semantic mark-up as viewed in Firefox.

Sample page using non-semantic mark-up as viewed in Firefox. Give or take a few pixels these look pretty much the same.

Sample page using semantic mark-up as viewed in Internet Explorer 6. As you can see, the banner breaks in IE 6 but everything else looks pretty much as expected. The page also breaks in IE 7 and IE 8 though the IE 8 version looks different. I've included these samples as a reminder to always check sites in multiple browsers.

Sample page using non-semantic mark-up as viewed in Internet Explorer 6. Again it looks almost the same at the semantic version, even breaking in the same manner.

The other day, Aaron Rester posed this question on Twitter: Webbies: any advice on explaining semantic HTML to non-webbies?

I wrote back that I usually show them some source code and walk them through things like using h1 and so forth for headers. That is what I usually do. In fact I'd just done that the other day when I was showing someone the changes I would recommend for search engine optimization (SEO).

But the question made me wonder if my explanations were adequate. If someone doesn't know anything about HTML or other mark-up languages, will such an explanation make sense? Or is there a better way to explain the differences between structural and presentational mark-up to clients and new Web designers?

Why do clients and other non-webbies need to know about semantic HTML?

Typically this topic comes up most often when one is discussing issues related to search optimization and accessibility. If a client needs to enhance their site for SEO, I may be recommending changes to the code that they won't even see when looking at the page in their browser. Understandably they will want to know why they should pay me to do things to their site that they won't notice. The changes we make may not be visually apparent, but they will convey additional information to Web browsers and search engines that can aid accessibility, usability and searchability.

What is semantic HTML?

Semantics is the study of meaning. Merriam-Webster's Online Dictionary provides us with a definition that relates closely to how the term is applied to HTML "3 a : the meaning or relationship of meanings of a sign or set of signs; especially : connotative meaning." HTML uses elements that convey structural meaning to Web browsers and other user agents such as search engine crawlers.

Writing a page in semantic HTML simply means that you are applying the appropriate structural elements to the various bits of content on a page. Huh? Code elements act like labels that tell the Web browser what each section of content is. HTML gives us structural elements to indicate headers, paragraphs, lists, tables and so forth. If I want to tell the browser to start a new paragraph, I'll type <p>. If I want to start a new subhead, I'll type <h5>.

Then isn't all HTML semantic?

You would think so, but no. Web browsers can be both fussy and forgiving. I can code the same content in multiple ways that will each look very similar when viewed, but will actually convey differing amounts of information to user agents.

Instead of using an <h5> I could use <p><strong>in front of my subhead and make it look the same as it would using <h5>. Such usage would be considered presentational mark-up. It can affect how the header looks, but it is not semantically correct because it doesn't let user agents know that this is a subhead. If a Web designer applies the incorrect elements to page content, the site may look perfectly acceptable. But it is not passing on vital information that user agents may need to:

• Help a visually impaired visitor navigate the page using screen reading software.
• Tell Google and other search engines what topics are the most important ones on the page.
• Show that you are citing a reference document such as a book.
• Indicate that you are presenting computer code, etc.

Same content, different mark-up

To illustrate this point I've created 2 very simple Web pages, one uses semantic mark-up and one using non-semantic mark-up. Basically the non-semantic version uses <p> for just about everything. When you view the pages through a regular browser you'll see that the semantic and non-semantic versions look pretty similar. They both look normal in Firefox, Safari and Opera, and they both break in various versions of Internet Explorer. You don't see the difference visually until you look at the pages in the text browser, Lynx.

When viewing the semantic page on Lynx, we can see that there is order to the page; it looks a bit like an outline. The menu looks like a menu and the headers standout to provide an introduction to the other text.

HTML elements in action, offering added information to user agents

Text readers for the visually impaired and search engine spiders are getting even more information than we can see in the Lynx semantic html example. They know that each menu link should be distinguished from the next. The use of an unordered list for the menu tells user agents to separate these links in a way that use of <p> does not, and allows users of screen readers to jump through or skip these elements to proceed to the main text. In the non-semantic version this is not clear, a text reader may speak all of those links together, making it more difficult for the user to navigate.

These user agents can also tell that the first header is more important than the second because it has been coded as an <h3> while the second header is an <h4>. Headers are ranked in order of importance from 1-6. Here we're using an <h1> for the site name, the most important header on the page. Search engine crawlers will see words in an <h1> as being more descriptive of the page as a whole. This is useful for search engine optimization, because we can include our keywords and phrases in our various headers to let the search engines know that core topics we are covering on the page. Thus on this page you'll notice that I've used the phrase "semantic HTML" in both the text and subheads (which in this case are <h5>'s.) That said I've not used it in every subhead because having these headers make sense to you, the reader, is still more important than SEO. People come first, then robots.

In this example I've focused on just a few a few of the many HTML elements that are important to semantic mark-up, but hopefully these will give you a clearer sense of how such usage can help SEO and accessibility. Other elements such as address, cite and blockquote can add additional meaning to a page's code. You can learn more about other elements and related issues in the reference links below.

Semantic mark-up, validation and content

It's always a good practice to validate your code to check for errors and potential problems, but site validation doesn't guarantee that you've used the best mark-up for the site. While the validator can make sure you've used allowed elements, it has no way of knowing if you've them in the most appropriate manner. Both the semantic and non-semantic page samples used in this post were produced using valid W3C standards compliant XHTML and CSS. One is clearly better formed than the other, but both also break in Internet Explorer.

Thus it's also important to check sites in multiple browsers and to simply think carefully about how visitors will read the site. If my samples were for real sites, I'd fix the IE problem, but I used it here to remind us that using valid semantic code is just the beginning. There will always be additional details we must consider.

It's also worth noting that, when it comes to SEO, a semantically well-formed site is not a substitute for good content. Search engines such as Google are designed to help users, like you and me, find the most relevant pages for the information we seek. With that goal in mind they have to accommodate a wide variety of coding differences. If your competitor has great content and plenty of good inbound links, while yours does not, then his/her site will still win out, even if the code is atrocious. But if you can produce great content and present it in the appropriate format you will be off to a good start.

Semantic HTML Resources

• The Elements of Meaningful XHTML (presentation showing examples)
• Fangs Screen Reader Emulator
• Guide to Semantic Use of HTML Elements
• Illinois Information Technology Accessibility Act Implementation Guidelines for Web-Based Information and Applications 1.0
• More than one H1 on a page: good or bad? (Video by Google's Matt Cutts)
• Semantics in HTML 5
• W3C Semantic Data Extractor
• W3C: G115: Using semantic elements to mark up structure

Last week's entry on outbound links spawned a lot of discussion, including the question of whether one should have outbound links open in a new window (or tab depending on the user's browser and preferences). Although many others have already written about this topic, it comes up often enough that I think it is worth discussing. Disclaimer: links that open in a new window or tab—when that wasn't my choice—are a pet peeve of mine, but I will attempt to explore the topic objectively.

What is the intended purpose of having links open in a new window or tab?

Those who recommend having links open in a new window do so with the intention of making it easier for users to return to the original site. Anyone who surfs the Internet knows that it is easy to get lost down a rabbit hole of links. For example, if I provide you with a link to Chuck Palahniuk's Web site, you might:

• follow the link
• peruse the section on author interviews
• read Dennis Widmyer's latest interview with Craig Clevenger
• then decide to add The Contortionist's Handbook to your Amazon shopping cart.

By now, the theory goes, you will have either forgotten where you were before or forgotten how to get back. If I'd set the Chuck Palahniuk link to open in a new window/tab (this is the only link on the page that opens a new window), you could just go back to your original window/tab and you'd be back where you started. Of course if the link opens in the same window, and you are using a current browser such as Firefox, you can simply click the down arrow next to your back button to navigate back through the series of links you just followed.

So which is better? Is it easier for a user to go back to a different window or to just use the back button?

I've always found it easier to use the back button. With one click I can go back and read another interview or I can choose to go all the way back to the original blog. To me that seems far easier than wading through a sea of windows, or looking at an array of tabs to find the one you want. But everyone is different. In researching this article I discovered a Get Satisfaction page in which a user actually requested that links on Pownce open in a new window. Two of the responders agreed that they would prefer new windows, while two others (including Pownce/Digg designer Daniel Burka) disagreed. I saw these differing opinions in many places.

Where does that leave us? Preferences vary, so unless you survey the users of your particular site it may be difficult to determine if your audience likes or dislikes it when a link opens in a new window. Pownce was able to solve the problem by giving users a setting that lets them pick which behavior is the default while they're on Pownce. But that's not an option for most sites and blogs. With that in mind, I think it is most appropriate to leave it in control of the user. If a user wants to open a link in a new window he can do so by right-clicking (Windows) or ctrl-clicking (Mac) the link in question. I often open links in a new tab if I know that I'll want to flip back and forth between them. I just don't want them opening up new tabs spontaneously.

Standards and accessibility issues related to opening links in new windows

If you're in the pro new window camp, I've probably not yet changed your mind. But there are more issues to consider.

W3C HTML and XHTML Recommendations

The traditional way to have a link open in a new window is to include target="_blank" in the link. The target attribute is not included in the recommendations for HTML and XHTML strict, therefore sites using target with a strict doctype won't validate. From what I've gathered target is not included because not all browsers support the attribute, particularly when it comes to browsers running on mobile devices. (This may change in XHTML 2.0 as the attribute may serve new needs as mobile browsers evolve. A valid alternative is to use javascript.

W3C Web Content Accessibility Guidelines 2.0 (WCAG)

According to the WCAG Success Criterion 3.2.5, "Individuals who are unable to detect changes of context or may not realize that the context has changed are likely to become disoriented while navigating a site. For example: individuals who are blind or have low vision may have difficulty knowing when a visual context change has occurred, such as a new window popping up. In this case, warning users of context changes in advance minimizes confusion when the user discovers that the back button no longer behaves as expected." To avoid this confusion they recommend that users should be notified if a link will open in a new window and if possible be given the choice to not have it open in a new window.

Kant's Categorical Imperative: What if everyone did it?

While writing this I kept having a vision of wandering the Internet in a world where every external link opened a new window or tab. In this vision it was only a matter of minutes before there were so many tabs open in my browser that I had to use the left and right arrows to scroll through them. Worse yet, instead of tabs windows began spawning as quickly as Tribbles and suddenly my desktop was impossible to navigate. This made me think of Kant. In his first formulation of the Categorical Imperative he states that one should "act only in accordance with that maxim through which you can at the same time will that it become a universal law." While this idea was meant to deal with issues of morality, it's easy to see how it could be applied to lesser situations such as links opening in new windows. If links always opened in a new windows it would pose significant usability challenges.

Naturally most sites don't open everything in a new window or tab. If they did we'd all be swimming in windows. Instead, most site designers choose to open new windows only in particular circumstances. Some designers do this only for external sites while others reserve the technique for opening up .pdf files. While I'd still prefer that links open in the same window, giving me the choice of whether or not to open them in a new tab, I understand that many may disagree. Most people have committed one way or another with few remaining undecided. But, whatever your preference may be, I hope this discussion will help the next time you're debating where a particular link should open.

Learn more about opening links in pop-up windows or tabs

• Accessible Pop-up Links
• D. Keith Robinson's Gorilla Web Tips: Launching New and Pop-up Windows
• Don't let your web site fall out of the window: opening new browser windows
• How evil is the target attribute?
• New-Window Links in a Standards-Compliant World
• Open New Window Still Has Usability Issues
• The target attribute and opening new windows
• Top Ten Mistakes in Web Design
• WCAG 2.0: H83: Using the target attribute to open a new window on user request and indicating this in link text
• WCAG 2.0: SCR24: Using progressive enhancement to open new windows on user request

I've recently come to the conclusion that a great number of Web developers either don't know about Web standards, or simply don't care. For those who aren't already aware of the standards I'll offer a brief introduction along with resources for additional information. For those who don't care, or who are anti-standards, I'll offer some examples as to why I feel they're important. For those of you already in the know, feel free to add your own advice, examples or pet peeves in the comments section.

The reason for Web Standards

According to the Web Standards Project Mission, "The World Wide Web Consortium (W3C), along with other groups and standards bodies, has established technologies for creating and interpreting web-based content. These technologies, which we call "web standards," are carefully designed to deliver the greatest benefits to the greatest number of web users while ensuring the long-term viability of any document published on the Web."

Think of these as the rules of the road. When you are driving a car in Ohio you know you have to drive on the right side of the road, stop at stop signs, not enter an intersection unless there is room for your vehicle on the other side, yield to pedestrians, etc. If you are driving in Hong Kong you know to drive on the left and follow the various rules relevant to that jurisdiction. Following these rules makes the driving experience more pleasant for everyone; whereas ignoring these rules will, at best, annoy other drivers and, at worst, cause a traffic related fatality.

In most cases, a non-standard Web site isn't likely to cause fatalities, but anything is in the realm of possibility. Errors in formatting can cause content to render incorrectly. Imagine if the word "Never" wasn't visible to users reading the sentence "Never pour gasoline on an open fire." A reader unfamiliar with the combustible nature of rising gasoline vapors could easily immolate himself. That's an extreme example, but whether your site is about fire prevention or your book club, you probably don't intend to misinform or confuse your readers.

Following Web standards lets you increase the odds* that your site will be properly rendered by most browsers and user agents and that your information will be more accessible to users and search engines.

* I say "increase the odds" rather than "guarantee" because there are still differences between the way browsers interpret the standards.

What are the Web Standards?

Different standards are available for different purposes, but for the most part standards will define the type of coding that you should use when creating a Web page or stylesheet, or the procedures or policies you should consider when creating the site. Thus if you are building a site in HTML using Cascading Style Sheets, and want to ensure your site is Section 508 compliant for accessibility, you might follow the standards for HTML 4.01, CSS 2, and Section 508.

For example, HTML standards specify using <p> to start a paragraph, <h1> for a primary header and <em> for emphasis. CSS standards specify things like color and position, so that a purple header could be defined in a stylesheet by: h1 {color:#571963}. Using a descriptive word or phrase in the alt tag of images conforms to accessibility standards (both 508 and WAI).

One of the most overlooked HTML standards seems to be the inclusion of the correct document type. For example, if you are building a site using XHTML 1.0 (as is true of many Case sites) you would include this document type:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"  
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

This small piece of code tells browsers and user agents what version of HTML you are using, so they don't have to guess when rendering the site. This is like telling Babel Fish whether you want to translate a phrase from Dutch to English or from German to English. If you don't give it the right information you may not get the right result. I'm amazed by the number of sites don't include this basic information.

Another important standard for HTML 4.01 and XHTML 1.0 is the separation of format and presentation. <h3>Headline</h3> is an example of format, indicating that something is a header. Styling the <h3> with CSS, either in the document or in an external stylesheet, to be a certain size, color and font would be an example of presentation. In the old days of the Web this was done within the HTML using the now deprecated <font> tag. In the past one might have typed <h3><font color="33ff33" size="5">Headline<font></h3>. This not only filled up your page with a lot of extra code, but it also meant that if you decided later to make all of your <h3>'s a different color you would have to go and change all of the font codes one by one. When using a style sheet you can define how your <h3>'s will look in one place. To change the color you just make the one change in the stylesheet and you are ready to go.

Separation of format and presentation isn't a particularly new idea, but adoption has spread slowly. CSS 1 was first introduced in 1996 and the CSS 2 recommendation has been around since 1998. While many sites use CSS, it is still not uncommon to stumble upon current sites that are still using older codes such as <font>.

Why this has been on my mind

A few weeks ago a friend sent me a link to a pretty cool looking site for an online magazine. Alas the site wasn't standards compliant and therefore didn't work properly. This particular site was Flash-based with dimensions too big to fit my screen. The page had no scroll bars so I couldn't get to the menus to navigate through the site. I could see the whole site on my Mac, but not on my Dell, and I'm pretty sure I'm not the only one to have had that problem. Since I couldn't navigate the site, they might as well have posted a page that said "Do Not Enter. We don't care about your business." If they had built a compliant site they would have ensured greater accessibility to users and not had this problem.

I've found a number of other non-compliant sites while working to compile a list of local Web developers. Departments without Web staff often look to outsource their Web projects and turn to me for referrals. Thus I'm trying to put together a list of local (to support the regional economy) developers who I can trust to build compliant sites that follow the Case design scheme, maintain a logical navigational structure and support the goals of the client. This has not been an easy task.

The problem is that almost anyone can learn to build a Web site, but only a few can do it well. There are a lot of firms out there, but the quality of work varies dramatically, and only a handful build standards compliant sites. Sites with major compliance errors don't end up on my list. This isn't just because I'm persnickety. If a site fails validation because of a few stray &'s or they've forgotten to close a few <p>'s I'm not worried. Such errors are easily corrected and don't disturb the overall functionality of the site. But if a site uses <font> tags, doesn't include a doctype, leaves alt tags blank on all of their images, etc., then I will conclude that its designers are not professional and will not be able to offer the client the advice or service necessary to implement a successful site.

Conclusion and Disclaimer

If you've ever built a Web site, you've followed at least a few of the standards. The site wouldn't work if you hadn't. For example if you left out the <body> tag your page wouldn't render. Since we're all following some of the standards anyway, I would just encourage everyone to learn and apply more of them. As you become more familiar with them you'll find that your sites become both easier to use and easier to build. To learn more about Web standards visit The Web Standards Project and the resources below.

Standards compliance is an ongoing goal of mine, but I'm only human. Not every site I've built is standards compliant, and the errors become more egregious the older the pages may be. Since I readily acknowledge this you don't need to go hunt them down, they are out there, and I know it!

Web Standards Resources

• Asterisk Web Standards Archive
• Designing With Web Standards, Second Edition by Jeffrey Zeldman
• Jeffrey Zeldman: King of Web Standards (Business Week)
• Section 508: The Road to Accessibility
• The Web Standards Group
• The Web Standards Project
• W3C Cascading Style Sheets, level 2 CSS2 Specification
• W3C Cascading Style Sheets, level 1
• W3C HTML 3.2 Reference Specification
• W3C HTML 4.01 Specification
• W3C XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition)
• W3C Technical Reports and Publications
• Web Accessibility Initiative (WAI)
• World Wide Web Consortium (W3C)