Use data validation rules with special phone and social security formats

- [Instructor] If you work with phone numbers … or zip codes or social security numbers … within the United States and you're using Excel, … you should be aware of some special built-in formats … and also some techniques that you could be using … with data validation to screen out some bad entries. … Let's first focus on the phone numbers … in columns A, B, and C. … In that pink panel are three different ways … to display phone numbers. … But regardless of which one you prefer, … take the attitude that you will only type the numbers, … don't type the special characters. … The more you type, the more opportunity for errors. … The entry we see in column A … actually is a built-in format in Excel. … I haven't used it on these cells here just yet. … Let's imagine I will be filling in other entries … in column A, so I'll simply select column A … and use this built-in format. … Press Control-1 to get to Format Cells. … That's one of a number of ways to get there. … And in this Format Cells dialog box, …