When composing word processing documents, or otherwise handling text on your Mac, you might find yourself needing to use special symbols, be it something simple like a star, bullet, or check, or perhaps something more unique like a math symbol or foreign language character. To provide you with this, OS X supports a full set of unicode fonts, and if special characters are needed then there are a couple of quick ways to access and manage them.

The central location for such characters are Apple’s Character Viewer panel; however, Apple has classically made a number of these characters available on the keyboard when using combinations of modifier keys. You can see these by opening a TextEdit document, then holding the Option key while pressing other alphanumeric and punctuation characters.

Memorizing which key corresponds to a specific character might be a bit of a chore, so to help you can use Apple’s keyboard viewer panel:

1. Go to the Keyboard tab in the Keyboard system preferences
2. Check the “Show Keyboard & Character Viewers in menu bar” option
3. Access the new menu on the right-hand side of the menu bar
4. Select the “Keyboard Viewer” option

When you do this, a panel representing your current keyboard layout will appear, showing you which characters will be entered when you press the corresponding key on your keyboard. Now if you press and hold various modifier key combinations (Shift, Control, Option, etc.), you will see the keyboard viewer change to show the new characters that are represented by each key with this modifier pressed.

One convenient use of this is to add accents to vowels and other characters that support them. For example, to add a diaeresis (two dots) over the letter “u,” you can first type Option-U to input the diaeresis, followed by typing the “u” letter (or any other that supports the diaeresis) to input that modified letter. The same goes for acute, grave, circumflex, and other accents.

While the keyboard viewer will show you a number of pre-defined alternative symbols, the main source for such symbols is the Character Viewer panel, which can be found in this same menu, or optionally invoked by pressing Option-Command-T in applications that allow this hotkey.

Similar to the keyboard viewer, the Character Viewer shows in a separate panel, but will give you access to all unicode characters, and offers them in a fairly organized list of categories.

When you first open the Character viewer, you will see only a few of the more common categories, but you can enable others by clicking on the gear menu and choosing “Customize List,” followed by checking the box next to the character categories you want to add.

In addition to browsing for various characters and symbols, you can also search for them by name. For instance, if you know you want to find the specific “cylindricity” technical symbol, then while you locate the “Technical Symbols” category and browse for it, you can simply search for the name. Doing so will show the typed characters of the name you enter, but also any symbols who’s name match the entered search term.

Final conveniences of the character viewer include the Recently Used and Favorites category sections, where you can access the symbols that you regularly use.

The character viewer can also be used for accessing some very uncommon characters as well. For instance, a specific situation would be to replace group separator symbols in a CSV file with a hidden ASCII group separator, such as ASCII character ^29, so the file will properly import into a database or other application you are using. To do this, you can open the CSV in TextWrangler and then use the “Find/Replace” function to search for the current separator character, and then activate the Unicode code table category in the Character Viewer, followed by locating and dragging the ASCII character ^29 to the “Replace” field to swap out these characters.

While this is a specific example, other text-handling routines like this can be performed by similarly using the Character Viewer with a program like TextWrangler.