Name syntax rules:
The Name string must begin with a text character, not a number, and consists of adjacent characters.
Two words can be joined with an underscore (_). For example, to enter the Name "Excel Book", you should type Excel_Book.
You cannot use a Name that could otherwise be used as a cell reference. For example, A1 or IS2002.
There is no limit on the number of Names you can define.
Be sure to define unique Names for a specific workbook. Defining Names that resemble Names in other sheets will only complicate your work.