Tooltips – the little yellow rectangles of information that pop up when you hover your cursor over something – do more than just describe the name and function of a button on a toolbar. You can use them to find the full name or path of a file in the Finder, to get a quick summary of a help topic, and more. (Note: Apple now uses the term “help tag” instead of “tooltip” in its documentation.)

See a file’s full name 
Almost anywhere the Mac shortens a name in a narrow column, you can use a tooltip to display its full name (see ‘Full names’). 

Hover your cursor over the truncated name in a list, a Finder sidebar, an Open or Save dialog box, in your Apple Mail message list or sidebar, or in the Source list (the area that’s like a sidebar) in iPhoto.

Sometimes doing this will reveal extra information. For example, in the Spotlight menu, a tooltip shows not only the full version of a shortened name, but also the item’s file path. In iPhoto, hovering over an album name shows you how many images it contains.

Outwit false links in Mail
An embedded link in an innocent-looking email message may be labelled “Important Info” but could actually take you to a phoney website. Check the URL of a link by waiting for its tooltip to pop up before you click on it.

Quickly view names of attachments in Mail
Suppose you receive a message asking for feedback regarding the Solution file – but the message comes with six attachments, all of which have truncated names. The quickest way to figure out how to address this is to hover over the icon of an attached file to see its full name, along with other useful information such as its download status. (To see the document’s contents, click on the document icon to select it, and then press the spacebar to open it in Quick Look.)

Find contact information fast
Spotlight makes it easy to look up a colleague or friend whose name is in Address Book. Activate the Spotlight menu (C-spacebar), 

type a name, and a list of possible matches will appear. Often the person’s name is the Top Hit in the menu. Press the Return key and Address Book will open up on that entry. 

However, if you want the person’s telephone number, you don’t have to go that far. Just hover your cursor over their name in the Spotlight menu to see all the phone numbers associated with it. 

Get help fast
You’ve done a search in the Mac Help system (choose Help > application name from within the program you need information about) and now you have a list of topics. But which topic should you check first? 

It would be easier to decide if you could read more than just a one-line description. Hover your cursor over a topic and a tooltip will appear with a complete description.

See Font Book info 
Sometimes it seems that Font Book has more numerous, and more useful, tooltips than any other Mac utility.

Want to know how many fonts are in a library or collection without deselecting the current one? Point to the library name and the information appears in a tooltip. Wondering how many typefaces are in a font but don’t want to have to select it in the Font list and expand it? Hover over the font family name to see the answer.

Say you have duplicate fonts and need to check which might be TrueType and which OpenType, which is the newer version of the font, and where the files are stored on the drive, all so you can decide which ones you want to disable or delete. You don’t have to switch to Font Book’s Info view; just point to the typeface for an informative tooltip with all the details you need (see ‘Font book details’).