DrawingML - SpreadsheetML Drawing
Within a SpreadsheetML document, it is possible to include graphical DrawingML objects:
Pictures (§5.2)
Locked Canvases (§5.4)
Diagrams (§5.9)
Charts (§5.7)
When these objects are present in a spreadsheet document, it is necessary to include information which specifies how the objects shall be positioned relative to the parent worksheet.
example: : Whether the object is anchored to a specific row, whether it resizes with cells, and so on.
The SpreadsheetML Drawing namespace acts in this capacity, specifying all information necessary to anchor and display DrawingML objects within a spreadsheet document.
example:
<xdr:twoCellAnchor>
<xdr:from>
...
</xdr:from>
<xdr:to>
...
</xdr:to>
<xdr:graphicFrame>
...
<a:graphic>
<a:graphicData
uri="http://schemas.openxmlformats.org/drawingml/2006/diagram">
<dgm:relIds xmlns:dgm="..." xmlns:r="..." r:dm="rId1" r:lo="rId2"
r:qs="rId3" r:cs="rId4" />
</a:graphicData>
</a:graphic>
</xdr:graphicFrame>
</xdr:twoCellAnchor>
The <twoCellAnchor> element (§5.6.2.32) specifies that this object anchored to the cells specified by the <to> (§5.6.2.31) and <from> (§5.6.2.14) elements. ]