Hidden under a menu named "preferences" or "Tools/Options," you will find a funny little control panel that contains a piece of software's heart and soul.

A common justification for preference panels is that there needs to be a way to customize programs, because each of us has different needs. An alternative explanation is that preference panels are a mark of neglect: unable (or unwilling) to figure out the "right" way to do something, the development team has thrown up its hands and dumped the decision on the user.

Both views have merit. Microsoft Word sensibly allows you to control whether to display formatting marks for tab characters, spaces, and end-of-paragraph marks. If you're writing letters to Aunt Jane, you probably don't want to see all of this visual clutter. But if you're editing a book or a magazine article, this kind of visual cue can be essential. On the other hand, Word developers abdicated their responsibility in the "Compatibility" panel, which allows control over such minutiae as whether SBCS characters should balance DBCS characters. I don't even know what these settings mean (apparently they relate to making documents compatible with previous versions of Word), but the developers did, and they should have picked the correct settings to ensure compatibility.

When I get a new program, one of the first things I do is systematically go through all of the options to see what the program is capable of. That's how I learned that Word has the ability to protect files so that they can't be read by someone who doesn't know the password ("Options/Security"). I discovered that Microsoft Outlook Express has an option to automatically spell-check my e-mail messages before sending them ("Options/Spelling"). And it turns out that my HyperSnap-DX screen capture utility can automatically scroll a window when taking a screen shot ("Capture/Capture Settings/Auto-scroll window"), which is great for capturing shots of really long Web pages.

Sometimes preference panels hide where you don't expect them. Find these panels: learning their powers will increase the number of things you can do with your software. For example, many programs can save documents in a variety of file types, such as text or rich text -- two formats that can almost always be imported into other programs. You can usually find these types by choosing the "Save As..." menu option and then clicking on the "File Type" pull-down menu. But if you want to tell your Hewlett-Packard ink-jet printer that you're using photo paper instead of plain, you'll need to first open up the "Print" panel, then click on a button that says "Properties," and then select the "Paper" tab. Explore the other tabs and you will find a way to enable two-sided printing, print several page images on a single side of paper, or even print a watermark that reads "for internal use only" across every page.

Like strata in a city or scars on a soldier's back, preference panels frequently document past battles -- either between the programmers and the project managers who created an application or between the company and its competitors. Microsoft Word versions for DOS displayed white text on a blue background; Word 2003 has an option to revert back to this prehistoric display, even though the color combination doesn't work well with today's fonts. Sadly, even companies that claim to care about usability keep loading more options into preference panels with each successive release of their software. For example, version 4.6 of Apple's iTunes program has seven(!) tabs on its preference panel, including one labeled "Advanced" that leads to a confounding assortment of additional choices.