A defined name in a formula can make it easier to understand the purpose of the formula. For example, the formula =SUM(FirstQuarterSales) might be easier to identify than =SUM(C20:C30).
Names are available to any sheet. For example, if the name ProjectedSales refers to the range A20:A30 on the first sheet, you can use the name ProjectedSales on any other sheet to refer to range A20:A30 on the first sheet.
Names also can be used to represent formulas or values that do not change (constants). For example, you can use the name SalesTax to represent the sales tax amount (such as 6.2 percent) applied to sales transactions.
Note By default, names use absolute cell references.
What characters are allowed? The first character of a name must be a letter or an underscore character. Remaining characters in the name can be letters, numbers, periods, and underscore characters.
Can names be cell references? Names cannot be the same as a cell reference, such as Z$100 or R1C1.
Can more than one word be used? Yes, but spaces are not allowed. Underscore characters and periods may be used as word separators
How many characters can be used? A name can contain up to 255 characters.
Are names case sensitive? Names can contain uppercase and lowercase letters. The Spreadsheet Component does not distinguish between uppercase and lowercase characters in names. For example, if you have created the name Sales and then create another name called SALES in the same spreadsheet, the second name will replace the first one.