Office Open XML - how to add additional Information to Presentation?

Question

I would like to store akey / value pair into my presentation (basically a GUID to know if I have seen the file before). I know that excel and word have extended properties, which can be used to store this kind ofinformation. But I am unsure if I can store similar Information in a Powerpoint-Document? Could someone point me to the right documentation?

Answer 1

I store key/value pairs in Shape.Tags. I can see them in X.pptx\ppt\tags\tag*n*.xml. Use VBA to save something there and you should be able to find it in the XML, or in the code generated by the Open XML SDK.

Answer 2

To add to Oliver's response, shapes, slides and presentations can all have tags.

For example:

Sub Example()
  With ActivePresentation
    .Tags.Add "SEENBEFORE", "YES"
  End With
End Sub

Sub AnotherExample
  With ActivePresentation
    If .Tags("SEENBEFORE") = "YES" Then
        MsgBox "I've seen it all before."
    End If
  End With
End Sub