In SpreadsheetML, cell references range from column A1–A1048576 (column A:A) to column XFD1–XFD1048576 (column XFD:XFD).

An implementation can extend this range. However, to avoid ambiguities, it is necessary to ensure that defined names are distinct from cell references, or that one takes precedence over the other. With this in mind, the following rules apply:

  • A producer or consumer shall consider a defined name of the form used by cells in the range A1–XFD1048576 to be invalid.

  • All other names outside this range can be defined names and shall override a cell reference if an ambiguity exists.