2.4.858 BrtWsDim

The BrtWsDim record specifies the used range of the sheet. It specifies the row and column (1) bounds of used cells in the sheet. Used cells include all cells that contain formulas (section 2.2.2) or data. Used cells also include all cells that have formatting applied directly to the cell. Cells can also be formatted by default row or column (1) formatting. If a row has default formatting, then the used range includes that row in its row bounds, but does not affect the used range column (1) bounds, unless the used range would otherwise be empty, in which case the column (1) bounds are set to include the first column (1). If a column (1) has default formatting, then the used range includes that column (1) in its column (1) bounds, but does not affect the used range row bounds, unless the used range would otherwise be empty, in which case the row bounds are set to include the first row.

rfx (16 bytes): An UncheckedRfX (section 2.5.154) that specifies the row and column (1) bounds of all the used cells in the sheet. If no cells are used in the sheet, then this value MUST be 0.