2.1.1118 Part 4 Section 3.18.64, ST_Ref (Cell Range Reference)
a. The standard does not clearly define what constitutes a valid a cell range reference.
In Office, a cell range reference consists of two single cell references separated by “:” character. The first single cell reference corresponds to the cell with the smallest row and column numbers, and the second single cell reference corresponds to the cell with the largest row and column numbers within the range. If both references correspond to the same cell, only the first reference might be recorded, and both “:” and the second reference might be omitted:
<cell range reference> ::= <cell reference> “:” <cell reference> | <cell reference>
The cell reference, the encoding of column names and their mapping to column numbers are described in ST_CellRef simple type (“[ECMA-376] Part 4 §3.18.8; ST_CellRef (Cell Reference)”).
The width of the cell range reference is equal to the difference between the largest column number and the smallest column number of the cell range reference, plus 1.
The height of the cell range reference is equal to the difference between the largest row number and the smallest row number of the cell range reference, plus 1.
A1:AD5 – a reference to the cell range of 150 cells, with top left corner in the cell at column , row 1, and the bottom right corner in the cell at column 30, row 5. The width of this range is 30 columns, and the height of this range is 5 rows.
XFD1048576 – a reference to the cell in the bottom right corner of the sheet.