Search billions of records on

Compatibility and Technical Information About These Documents

This page provides technical information about these Web pages, the standards they conform to, compatibility and incompatibilities you may expect with various browsers, and what's in their guts. All this information applies to each page that links to this page.

Viewable With Any Browser

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

I have used 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's what I know that might affect you. Please let me know of any problems you discover in my pages.

recognizing a Web page
Most browsers will try to display any Web page. Internet Explorer Version 5.0 for MacOS fails to recognize some pages, displays an incorrect error message, and refuses to show the pages at all. This happens with XML documents that have DOCTYPE declarations. Version 5.1.5 fixes the problem.
images and other media
Many of these pages use embedded images. If you're using a text-only browser such as Lynx, or if you prefer to turn images off in your browser, you won't see them. In every case you should see a text description of what the image is. Simple pictures are the only media that display inline in these pages. I have a separate discussion of other media, plugins, and Java applets.
image file formats
All of the images on these pages use the file formats PNG (for line graphics) or JPEG (for photographs). I have a separate discussion of why you see no GIF files here. Although JPEG recently acquired some of the same difficulties as GIF, I have not tried to convert my JPEG files to anything else. Both these formats are supported by every browser I have ever tried that supports graphics at all. I have tested and found good native built-in support with no plugin needed or other difficulty using PNG and JPEG files in Internet Explorer Version 4 though 6 for Windows, Internet Explorer Version 4 though 5 for MacOS, Netscape Version 4 through 7 for Windows, Netscape Version 3 through 4 for MacOS, Netscape Version 4 through 7 for Solaris, Opera Version 6 for Windows, Amaya Version 6 for Windows, or Mosaic Version 1 for AmigaDOS. Not all of these handle images that are intended to have transparent parts.
transparent image backgrounds
Internet Explorer Version 5 gets them right, Netscape Version 7 still doesn't. Some images are supposed to let the background of the page show through transparent parts of the image. With browsers that support transparent backgrounds they look much better.
No browser, not even Amaya, gets them completely right. The latest versions are pretty good. I discuss this more in the section on style.
following a link
This is basic to the Web, so it's surprising that Netscape Version 7 still doesn't support links to elements in a document other than to the a element. Internet Explorer Version 6 does. I have kept the old-style HTML a element with a name attribute, even though that has been deprecated in XHTML Version 1.0. Also, Netscape Version 4 does not support using one anchor as both the source or one link and the target of another. I have tried to avoid using anchors in that way, but sometimes it's exactly the right thing to do. Someday I hope to make these pages conform.
table heads
No browser, not even Amaya, supports them. The standard suggests that browsers should make the thead element of a table always visible, and scroll a long table beneath it. This is very useful for long tables, but it doesn't work with any browser I know. There are tricks to make a long table scroll, but those tricks are only supported well by Internet Explorer Version 6. So I have not used them.
The two major browsers, Internet Explorer since Version 4 and Netscape since Version 3, support Javascript pretty well. Opera Version 6 tries to interpret the language but makes mistakes. Amaya does not do Javascript at all. HTML can support any scripting language, but nothing besides JavaScript is well supported in browsers. Microsoft promoted VBScript, but that only works for people who use Internet Explorer on Microsoft Windows. I currently don't use any scripts at all. If I decide to add Javascript in the future, I'll give warning.
applets and plugins
The advantage of these is that they are standardized separately from the Web, so every browser supports them pretty well if it can do plugins and if you get the correct plugin. 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. I have avoided them in these pages. There's no Flash, no RealMedia here. There may be links to permit you to download MIDI or other files if you want them. As of this writing I use no Java applets. If I find a reason to offer one, the page that uses it will warn you.
Valid XHTML 1.0!

This page was written in XHTML Version 1.0, which is a recent version of the HTML family of languages. I chose not to use XHTML Version 1.1 because many browsers still in use don't handle it well. One of the purposes of XHTML is to support XML extensions on the Web, but only the newest versions of browsers understand and display them. I haven't made use of anything outside the XHTML standard yet.

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

Note that pages I publish on Rootsweb are altered by Rootsweb's server. Rootsweb adds its own advertisements at the top and bottom of each page. In my opinion, this is a fair fee for the space and Web services Rootsweb gives me. But it means I can make no claim or guarantee about anything Rootsweb adds to a page after I place it on that server. In general, pages rewritten by Rootsweb's server are not valid HTML.

Uses Cascading Style Sheets

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

  1. Browser vendors find style 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 through 7 all choose to render a style description of smaller text as very tiny. In my opinion, most browsers make a good enough effort to make 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. I agree with this in principle. 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 I believe we are many years from having a Web that actually works this way.

The underlying justification of CSS is to separate structure from presentation. I believe the benefits of CSS justify its use. 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 still 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 my style sheet with your own.

Valid CSS!

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

RDF Resource Description Framework Icon

I have provided descriptions of these pages in 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, I have put all RDF into separate files.

A single RDF description covers most of the content of these pages. Each of these pages contains an HTML link element to an RDF description, usually the same one. This has two advantages:

  1. It saves me repeating the bulk of the text in every page. Browsers that can't or don't want to read the RDF don't make you wait for it to download in every page. This also means if I update the RDF, I 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. I prefer putting it into an external file.

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.

RDF Resource Description Framework Metadata Icon

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

Dublin Core Icon

RDF supports a large universe of possible descriptions of Web content. I use 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.

contains Open Content

These pages are a volunteer hobby effort. I am happy for other people to benefit from any information I have to offer. I do hope that everybody on the Internet will always be honest and fair about using each other's contributions.

To promote free use of information, I copyright each page that is my own work and make it available under the Open Content License. The essence of that license is that anybody may copy and distribute the content with proper credit, and nobody may steal or plagiarize it. I do my best to give full credit to people who created other information, and I only use material I get from other people in accordance with the creator's rights and desires. I welcome feedback and will make corrections if I have attributed or used anything you find on my pages in error.

Free of .gif format graphics

This page contains no files that use the Unisys Graphical Interchange Format (GIF). There are three reasons for this choice.

  1. GIF is an old file specification, and has been superseded by technically better ones. Many of the graphics on this page use Portable Network Graphics (PNG).
  2. Several standards organizations recommend PNG in preference to GIF. I have tried to make these pages conform to universal standards so they will continue to be useful into the future.
  3. GIF was treated as a standard by CompuServe, and then later by early Web sites. After the Web became well-known, Unisys decided not to permit GIF to be used as a standard, but as a patented technology. Unisys now charges license fees to some classes of users if they execute programs that compress data into a GIF file. I agree with patents and licensing for inventions, but it is better to use standards than patents for things like file formats.

JPEG in the summer of 2002 also suffered a sudden change in status. It uses a patented compression algorithm that was formerly made available to the JPEG and ISO standards bodies. That patent was purchased by a company that began to bill some users for license fees. As a result, ISO has deleted JPEG as an international standard. There is nothing so far to replace its niche on the Web. I believe my current use of JPEG images on these pages is legal, so I do not plan to delete them. The JPEG patent will expire in 2004, so at that time all JPEG images are expected to be free of the threat of new license fees.

Top | Home | Site map | The author | © 2002, 2003 by Glenn Holliday RDF Resource Description Framework Metadata Icon Last updated: December 25 2003