How to use special characters in OS X
Every now and then you may need to enter special characters and symbols when writing, which can be for relatively common tasks such as character accents or "degree" signs, but also for more obscure or specialized symbols. In the past, many of these came from using special fonts (Wingdings or Dingbats) that contained these symbols as alternates to the standard alphanumeric characters, but these days fonts make use of the Unicode system and can include hundreds or thousands of available symbols.
As with other PC systems, the Mac keyboard layout is a standard one for the most commonly accessed characters, but you can also quickly access other common characters by using modifier keys. For instance, if you want to enter the degree symbol, you can use Shift-Option-8, or if you want a bullet symbol you can just press Option-8. There are others available as well, but without knowing where they are, it would take trial and error to figure it out.
To make things easier, Apple includes a couple of system utilities that can help you when you need to use alternate characters: the first is the Keyboard Viewer and the second is the Character Viewer. To enable these options, go to the "Language & Text" system preferences (called "International" in OS X 10.5 and below) and check the option to "Show Input menu in menu bar." Then in the list of input methods, check the options for the keyboard and Character Viewers (these are separate options in OS X prior to Snow Leopard). When the input menu is enabled, you may see it represented by a flag in the menu bar, though if you have only one keyboard layout checked then it will show as the Character Viewer icon in Snow Leopard.
Once this menu is enabled, you can access the Keyboard or Character Viewers from it.
In the classic Mac OS, one of the most useful features was "Key Caps," which for a while was left out of OS X but was brought back in the form of the Keyboard Viewer. Like its predecessor, the Keyboard Viewer allows for a quick look at all the characters that are available via the keys on the keyboard. By default it will show the standard keyboard layout for your system, but if you hold various modifier keys then the viewer will show the optional characters, including Greek letters, currency, accents, and even an Apple symbol.
To see these, open the Keyboard Viewer, then press various combinations of the Shift and Option keys. In addition, you can hold the "Fn" key down to see how it changes some of the action keys on the keyboard such as the Enter, Delete, and Arrow keys.
If you are managing character accents or other slight modifications to standard characters in the Keyboard Viewer, you may see them highlighted in orange. This means that when you first press the key for this accent character it will set it to be included with the next pressed character, if that character supports it. Therefore if you want to put an acute accent over the "O" character, you will first need to press the Option key and tap the "e" to select the accent character, and then press the "O" key to enter the desired "ÃÃ?" symbol.
In addition to showing the available characters, you can use the Keyboard Viewer to both track and enter key presses. When you press a button on the keyboard, it should highlight gray in the Keyboard Viewer, or if you click a key on the Keyboard Viewer then the character represented by that key will be entered to the system, and will show up in a document if you have one open.
The Keyboard Viewer will only show the most common characters for a given input layout, and while this can be changed to a layout that is most suitable for a different language, it is still limited to the most common characters for that language.
Despite this, there are thousands of available symbols in OS X that you can use, and these can be accessed through the Character Viewer, which should be in the same Input menu as the Keyboard Viewer. In Snow Leopard, Apple has updated the Character Viewer layout, but regardless of what version of OS X you have, you should be able to find numerous symbols in the fonts that are installed on your system. For instance, if you want an ornamental arrow character, select arrows and choose the one you would like, and then choose the appropriate one from the "collections" section of the Character Viewer where the viewer by default limits the fonts shown to those that only contain the desired character.
Making use of symbols
While there are many characters available in OS X fonts, their use is sometimes limited by the programs being used. Most editors are standard page layout processors that enter characters sequentially from right to left, and do not provide much support for alternative character placement. Despite this, in OS X when you select a language in the input menu, then the writing direction should change to the one supported by that method, so Arabic and Hebrew should write from left-to-right. Additionally, some word processors can be set up to enter characters vertically. In Microsoft Office this can be done by using the "Microsoft Language Register" utility in the "Additional Tools" folder that is included with the program. Once the language is set, more options will appear in Word to allow for vertical text placement.
Beyond character input options, one of the most common uses of alternate symbols is for science and math, particularly when generating complex equations and formulas. While the Character and Keyboard Viewers will allow you to access a number of the symbols required for these equations, most applications will display these in a linear fashion and not allow you to easily construct full equations.
Despite this, there are some options for doing this in OS X. The first is to use a third-party program like MathType, but there are also options for programs like Microsoft's equation editor for Word. Additionally, if you are familiar with the open-source typesetting system "LaTeX," you can use it to generate a variety of text forms, including equations.
Besides these options, you can use Apple's frequently overlooked "Grapher" program to create more complex equations that can then be used in other word processors. While not a complete solution, Grapher has enough options to make it useful for many equations. For more information on how to do this, see our mini tutorial on using Grapher as an equation editor.