Compatibility

This page should be viewable and useful with any browser at all that you might prefer to use.

This site uses only recommended techniques that have been standardized by the Web standards bodies since 1997 in HTML Version 4.0. Even browsers released before that date ought to do a good job showing you what's in these pages. If you wish, you can turn off cookies, Java, scripting, styles, and even images in your browser. You should still be able to use all of the content in these pages.

Unfortunately, following the standards is a hard job, and even the newest browsers have some errors in them. Here is a list of features that might pose problems for some browsers. Please contact us if you find other issues.

recognizing a Web page

Most browsers will try to display any Web page. Internet Explorer Version 5.0 for MacOS will not try to display XML documents that have DOCTYPE declarations. It displays an incorrect error message for these pages. Version 5.1.5 fixes the problem.

images and other media

All of the images on these pages use the standard file formats Portable Network Graphics (PNG) (for line graphics), the Joint Photographic Experts Group (JPEG) file format (for photographs), or the Unisys Graphical Interchange Format (GIF) (for line graphics). These formats are supported by every browser I have ever tried that supports graphics at all. You may see problems with images that are intended to have transparent parts.

Pictures are the only media that display inline in these pages. Other things such as music or video may be available to download from a link, but none of these pages automatically force you to download and play them. Anything that's not a picture needs a plugin.

There is some controversy surrounding the use on the Web of the GIF format. There are three issues at question:

1. GIF is an old file specification, and has been superseded by technically better ones.
2. Several standards organizations recommend PNG in preference to GIF. PNG files may be more likely to be useful 10 years from now.

3. GIF was created by CompuServe and used as a graphics standard, first on that service and then in the early years of the Web. Wang Corporation patented the algorithm used to compress a GIF file. That patent is currently owned by Unisys.

   Many technical bodies feel that patents are not the best tool to use to create file standards.

   More practically, Unisys charges license fees to some classes of users. At different times Unisys has published press releases that said they will and will not charge license fees to Web sites like this one if they display GIF images. Unisys' policy statement as of January 26 2003 says "reading and/or writing of GIF images requires a license" ... In all cases, a written license agreement ... is required from Unisys for all use of any software ... providing LZW conversion capability (for example, ... displaying GIF images)." This sounds like Unisys wants every one of you who uses a Web browser to get a separate license from Unisys before they will permit you to use your Web browser to look at a GIF image.

Because GIF is extremely widespread, both on the Web and in image processing programs from which members may provide images for this Web site, you will find it used here. If Unisys clarifies their policy for Web sites, VASA may ask for volunteers to convert all GIF images to PNG.

A patent that affects the JPEG standard was purchased by a new owner in 2002, who has suggested there is some risk of JPEG suffering the same fate as GIF.

transparent image backgrounds

Internet Explorer Version 5 gets them right, Netscape Version 7 still doesn't. You may find some images that would look better if you could see through them to the background. Indeed they would, and with browsers that support transparent backgrounds they look much better.

styles

No browser, not even Amaya, gets them completely right. Internet Explorer Version 5 and Netscape Version 4 aren't bad. There is a longer section on style.

finding where a link leads

This is basic to the Web, so it's surprising that Netscape Version 7 still doesn't support the standard that you should be able to link to any element in a document. These pages use the old-style HTML anchor element with a name attribute, even though that has been deprecated in XHTML Version 1.0.

Also, Netscape Version 4 does not support the standard that an anchor can be both the source and target of a link. This site avoids using anchors in that way, but many times it's exactly the right thing to do.

table heads

No browser, not even Amaya, supports them. The standard suggests that browsers should make the title row of a table always visible, and scroll a long table beneath it. This is very useful for long tables, but you won't be able to do it with any current browser. There are tricks to make a long table scroll, but those tricks are only supported well by Internet Explorer Version 6. This site does not use them.

scripts

The two major browsers, Internet Explorer since Version 4 and Netscape since Version 3, support Javascript pretty well. However, Opera Version 6 does not. It tries to interpret the language but makes mistakes. Amaya does not do Javascript at all. This site generally avoids Javascript. Any page that uses it has an explicit warning.

There is no other standard scripting language. Other choices like VBScript are only supported by a single niche vendor. This site uses no scripting other than Javascript.

Javascript was standardized by ECMA, and is now technically known as ECMAScript.

applets and plugins

The advantage of plugins to display specialized media is that they are standardized separately from the Web. Every browser that can add plugins will support every plugin equally well. If you have the correct plugin, the media that plugin plays should work on your browser. But not everybody has or likes the correct plugin. Also, many bits of content that require a plugin are large files that require a long time to download and play. There is nothing on this site that requires special plugins. There's no Flash, no RealMedia here. There may be links to permit you to download MIDI or other files if you want them.

This site currently uses no Java applets. If the site adds a compelling feature that uses one, the page that uses it will warn you.

This page was written in XHTML Version 1.0, which is a recent version of the HTML family of languages. XHTML Version 1.1 is not used here because many browsers still in use don't handle it well.

This page was validated to be correct HTML by the World Wide Web Consortium's validator service.

This page uses Cascading Style Sheets Level 2 (CSS-2). There is some debate over their use for two reasons:

1. Browser vendors find them hard to support correctly, so no current browser renders style completely and correctly. Some try but make odd choices about how things should appear. For example, Netscape 4, 6, and 7 all choose to render a style description of smaller text as very tiny. The benefits of style sheets outweigh this problem.
2. More philosophically, some argue that the Web page writer should not specify style at all, and leave all style interpretation to the browser. XHTML provides tools that I will eventually use to write a rich description of how the structural elements in my pages relate to each other, and browsers will be able to choose a style that expresses those relationships. But the Web does not yet actually work this way.

The underlying justification of CSS is to separate structure from presentation. Any browser should correctly display the content of these pages regardless of how well it does with their style. If your browser does not do style at all, you will have full access to all the information here. It might just look dull. If your browser does a poor job rendering CSS, you might consider turning styles off or overriding this site's style sheet with your own.

The CSS-2 style sheets used by this page were validated to be correct by the World Wide Web Consortium's validator service.

All of the links on each page were valid at the "Last updated" date at the bottom of the page. The Internet is always changing, so some of the links might have changed since they were last checked. Please let us know if you stumble on a broken link.

Each link on pages that link to this page was checked with the Big Brother link checker program.

Each page is described as metadata in the Resource Description Framework (RDF). RDF is a part of the Web standards that allows browsers and other programs to figure out what Web documents contain and mean. This will help future programs do a better job of finding the information you want.

XHTML 1.0 does not support RDF elements. Rather than hide RDF in comments inside HTML, All RDF into a separate file. Currently, a single RDF file describes the entire Web site. Each of the Web pages contains an HTML link element to that RDF description. This has two advantages:

1. It saves repeating the bulk of the RDF description in every page. Browsers that can't or don't want to read the RDF don't have to download in every page. When we maintain the RDF, we only have to do it once.
2. Because older browsers don't support RDF at all, nasty tricks are needed to hide it from browsers that might put it into your face rather than ignore it. Putting it into an external file avoids this problem.

Each page with its own specific RDF description contains this button, which links to the applicable RDF. Pages that link to the common RDF for the whole site don't have the button.

Each RDF description linked to by these documents has been validated using the World Wide Web Consortium's validator service.

RDF supports a large universe of possible descriptions of Web content. This site uses the Dublin Core set of metadata elements. This is one of the standard and widespread ways for programs and people to know what to expect in an RDF file.

One type of metadata used on the Internet is descriptions of the type of content. The Platform for Internet Content Selection (PICS) is a generic framework that can describe any attributes about a Web page. Most of the interest in this framework is for parents, schools, and libraries to judge the appropriateness of Web pages for children. This Web site uses the Internet Content Rating Association descriptions of chat, language, violence, and sex. (The VASA pages include none of these.) The ratings in these pages are self-applied. They are also found in the RDF description.