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This chapter is from the book

This chapter is from the book

Rename a Folder or Document

Before You Begin

Create a New Folder

See Also

Make an Alias (Shortcut)

Set a Color Label

Renaming a folder or document in Mac OS X is a seemingly simple process that hides some surprising complexity. On the face of it, there's really nothing to it: select the item, type the new name, and you're done. However, there are a few hidden complexities to watch out for.

In Mac OS X, filename extensions are often (but not always) required to define a document's type—but you don't have to see them. Extensions can be turned off on a per-document basis. If you rename the document in the Finder so that the extension is removed, the extension merely becomes hidden. Similarly, if you add the appropriate extension to a document, it merely becomes "un-hidden."

Figure 3.3Figure 3.3


Key Term - Extension—The often cryptic final few letters in a filename. Originally popularized by Windows, the extension is a simple way to designate a document as being of a certain type; this way, an application could know what kind of file it is just by looking at the filename.

By hiding documents' extensions, Mac OS X guarantees that the extension will be there if you transfer the file to a Windows machine, where extensions are required for documents to work properly.

A few common extensions are listed here:


Kind of Document


Picture (Joint Photographic Experts Group)


Picture (Graphics Interchange Format)


Microsoft Word document


Rich Text document


Plain Text document


QuickTime movie


Web page (Hypertext Markup Language)


Page layout (Portable Document Format)


Mountable Disk Image file


ZIP archive (Windows-style)


StuffIt archive (Mac-style)


AppleWorks document (originally ClarisWorks)


Use the Get Info palette to see whether a document has a hidden extension or not. You can also hide or show a document's extension using the Hide extension check box.

  1. Locate the Item to Rename

  2. Open a Finder window and navigate to the folder containing the document or folder you want to rename.

  3. Select the Filename

  4. For the item you want to rename, click the filename underneath or beside the icon. The item becomes selected (a darkened box appears around it) and the filename turns into an editable text field.


    In Mac OS X, if you click a text field (such as the name of a file in the Finder) and drag the mouse down, all the text to the right of where you clicked becomes selected. Similarly, if you click and drag up, everything to the left of where you clicked becomes selected.

  5. Type the New Name

  6. Type whatever name you like into the name field. Filenames can be any length up to 255 characters.

    You can use almost any letters, numbers, or symbols in filenames, including characters in Japanese, Russian, and many other languages. However, there are a couple of exceptions to this freedom. Colons (:) are not allowed in filenames because the internal architecture of Mac OS X uses the colon to signify the separation between folders in the path to an item. Similarly, you can't use a period (.) as the first letter of a filename because that character has special meaning for Mac OS X.

    Some applications might prevent you from creating files with a slash (/) in the name, or names longer than 31 characters. These are limitations in the applications (caused by the merging of Unix and of the old Mac OS), not in Mac OS X.

  7. Press Return

  8. Press Return to commit the change. Alternatively, click anywhere on the Desktop or the folder window to deselect the item and make the name change stick.


If you've accidentally started renaming an item that you don't actually want to rename, simply press Escape (Esc) to cancel the operation.

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