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Code:
Sub ResetCCs()
Dim aCC As ContentControl, iType As Integer
Dim bbCat As String, bbType As Long
For Each aCC In ActiveDocument.ContentControls
With aCC
Select Case .Type
Case wdContentControlText, wdContentControlRichText, wdContentControlDate
.Range.Text = ""
Case wdContentControlComboBox, wdContentControlDropdownList
.DropdownListEntries(1).Select
Case wdContentControlCheckBox
.Checked = False
Case wdContentControlBuildingBlockGallery
iType = .Type
bbType = .BuildingBlockType
bbCat = .BuildingBlockCategory
.Type = wdContentControlRichText
.Range.Text = ""
Do While .Range.Tables.Count > 0
.Range.Tables(1).Delete
Loop
.Type = iType
.BuildingBlockType = bbType
.BuildingBlockCategory = bbCat
End Select
End With
Next aCC
End Sub