There are many articles on how to write web pages for international audiences, such as my articles: Using Non-English Letters and Writing Websites for a Global Audience. But these articles don’t cover some important issues surrounding computer platforms, dates, and phone numbers.
Special Characters and Computer Platforms
Most platforms will support displaying the special characters, but some of them are a bit more esoteric, and so not all machines will display them correctly. The characters that cause the most problems are Ÿ, ÿ, Ð, ð, ß, and þ. If you are writing web pages in a language that uses these characters, make sure to test your pages in as many web browsers as possible, and on both Macintosh and Windows machines.
Dates on International Pages
Even if your web page uses only English characters, dates can be a problem. For example, if I write the date 08/10/12, what does that mean to you? If you're in the United States it means August 10, 2012. But if you're in other English speaking characters like the U.K. it means October 8, 2012. And of course, if you're writing a historical site, it could mean 1912, rather than 2012.
But there is a standard set for dates: ISO 8601 International Standards Organization format for dates. This standard format is:
CCYY-MM-DD
The codes mean:
CC—the century
YY—the year
MM—the month between January (01) and December (12)
DD—the day between 01 and 31
This standard is useful because it makes the dates programmatically accessible. Scripts like JavaScript can use it as well as PHP and databases like mySQL. But it's ugly. If you want your pages to look better and use dates, the best solution is to use words, either full words (i.e. January) or abbreviations (i.e. Jan), and then surround the entire date with the TIME element and use the datetime attribute with the date in ISO 8601 format.
Phone Numbers
Phone numbers are different all around the world. If your website caters to an international audience, you should indicate what country your phone number is in. Don't assume that your readers will know the country code, and leave it off. In fact, if you expect to get a lot of international calls, you should make it as easy as possible for your international customers to call.
I have found that U.S. websites make this mistake more often than non-U.S. It is very common to see a 7-digit phone number on U.S. websites. This is not even helpful in the United States—leaving off the area code is a common habit, but with nationwide and world-wide websites, the number is completely useless without the area code.
Then there are international codes. If you live outside the U.S. but your website caters to U.S. customers, you need to be very clear about the international calling code. Most Americans have no idea how to dial an international number. You should not assume that just because you've placed a +3712 at the front of your phone number will make it clear to most Americans that they are going to be dialing an international number to Tashkent, Uzbekistan. In fact, you should be as clear as possible saying something like:
To call us from the United States, first dial 011 and then ###.
A list of international calling codes is available online.
