• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint



United Kingdom.


This should be avoided on the Web except for hyperlinks, because readers have been conditioned to think that clicking on underlined text will link them to another part of your document, another document, or another website.

See also [formatting]
See also [links]

unique visitor

An individual visitor to a website within a specified time frame. For the unique-visitor measure, repeat visits by that visitor within that time frame are not counted by the site’s traffic measurement system.

See also [hit]


A powerful operating system developed by Ken Thompson and Dennis Ritchie at AT&T Bell Laboratories in 1969.


The unsubscribe process is the process by which a subscriber is removed from a subscription service. Make sure that the unsubscribe process is simple and clear.

Subscribers should be able to go to a website and enter their email address in a simple form to unsubscribe, and they should also be able to send an email to a special address with an “unsubscribe” instruction.

A common mistake many subscribers make is to forget the email address that they originally subscribed under, and then to try to unsubscribe using their current address. This will obviously result in a failure to unsubscribe. Therefore the following type of statement should be associated with the unsubscribe process:

Please remember to unsubscribe using the exact email address you subscribed with. To find this address, please consult the confirmation message you were sent when you joined the list.

Some subscription software programs have a facility whereby the email address that the subscriber is subscribed with can be published with each newsletter that goes out. This is highly recommended.

If for whatever reason the subscriber does not wish to unsubscribe using the normal channels, they should be able to easily contact someone in the organization, ideally by email, with a request to unsubscribe. Such a request should be treated with the highest priority and they should be unsubscribed immediately.

When someone successfully unsubscribes, they should be sent a “farewell message” informing them that they have been successfully unsubscribed and thanking them for having been a subscriber to the service.

See also [confirmation message]

uppercase, use of

See [capitalization]

Uniform Resource Locator: the address of a document or site on the Web. Avoid using end punctuation immediately following a URL in body text as the reader might include it when typing it in.

URL navigation

To make it easy for people to navigate to your site using your URL, choose the shortest, most memorable URL possible for the website. If you are aware that readers commonly misspell your URL, register the misspelling, then redirect that URL to the main URL. Choose all lowercase for your URL, as this is what readers are used to seeing. If the website has extensive content in a number of languages, then where possible get a URL for that country (.de for Germany, .ie for Ireland, etc.).

If the website has an extensive range of products, it may make sense to have a number of subsidiary URLs. For example, if you look for the iMac on the Apple website, you will find it under the following URL: www.apple.com/imac/. However, you will also find it under the shorter and more memorable URL: www.imac.com. Both URLs go to the same page.

If you are promoting a certain product or offering, publish the specific URL that will bring the reader to the relevant section on the website rather than the generic homepage. For example, if you’re promoting the iMac, you wouldn’t point the reader to www.apple.com. Rather, you’d point them to www.imac.com.

Once you’ve published a page with a specific URL, avoid deleting, moving, or changing the URL for that page, unless the content has gone out of date. If the page is linked to from other websites, the reader will be misdirected, and readers’ bookmarks will become invalid. If you do delete a page, try to re-direct the old URL to the most relevant homepage or document.

See also [navigation]

US dollars

See [foreign currencies]

United States of America.


From a Web perspective, usability refers to how easy it is for someone to use a website. Web usability examines the ease with which a reader can access pages on the website—whether they download quickly, whether they are compatible with that reader's browser, whether they are accessible to readers with disabilities. It looks at how easy it is to search, and the quality of search results that are returned, as well as how simple it is to navigate through the website. It also looks at how easy it is to complete tasks on the website, such as purchasing a product, getting in touch with the organization, and so on.

See also [accessibility]
See also [information architect]


A worldwide network (available at http://groups.google.com) used as a bulletin board system by special-interest discussion groups. Usenet comprises thousands of newsgroups, each devoted to a particular topic.

user agents

Software to access Web content, including desktop graphical browsers, text browsers, voice browsers, mobile phones, multimedia players, plug-ins, and some software assistive technologies used in conjunction with browsers such as screen readers, screen magnifiers, and voice recognition software.



Not a subscriber?

Start A Free Trial

  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint