Sub Main()
Dim oDoc As DrawingDocument
Dim oSheet As Sheet
Dim oView As DrawingView
Dim iter As Long

'check if active document is a drawing
If ThisApplication.ActiveDocument.DocumentType <> kDrawingDocumentObject Then
    Exit Sub
End If

oDoc = ThisApplication.ActiveDocument

iter = 1

'Rename detail and section view identifiers on all sheets
'Iterate through all sheets
For Each oSheet In oDoc.Sheets
    'Iterate through all views on sheet
    For Each oView In oSheet.DrawingViews
        If oView.ViewType = DrawingViewTypeEnum.kDetailDrawingViewType Or oView.ViewType = DrawingViewTypeEnum.kSectionDrawingViewType Then
            oView.Name = num2Letter(iter)
            iter = iter + 1
            If InStr(1, num2Letter(iter), "I") > 0 Or InStr(1, num2Letter(iter), "O") > 0 Or InStr(1, num2Letter(iter), "Q") > 0 Then
                iter = iter + 1
            End If
        End If
    Next oView
Next oSheet

End Sub

Public Function num2Letter(num As Long) As String
'converts long to corresponding alpha
'Ex. 1 = A, 28 = AB

remain = num Mod 26
whole = Fix(num / 26)
    
If num < 27 Then
    If remain = 0 Then
        num2Letter = "Z"
    Else
        num2Letter = Chr(remain + 64)
    End If
Else
    If remain = 0 Then
        num2Letter = Chr(whole + 63) & "Z"
    Else
        num2Letter = Chr(whole + 64) & Chr(remain + 64)
    End If
End If
End Function