Master Records - Formatting
The 'master' cell style record (<xf>) ties together all the formatting (e.g. number format, font information, and fill) for a cell's direct formatting. An <xf> inside <cellXfs> is referenced by zero-based index (not ID) (s) from a cell definition (<c>) in one of the sheets.
<cellXfs count="1"> <xf numFmtId="0" fontId="0" fillId="0" borderId="0" xfId="0"/> </cellXfs>