I recorded a macro while adding a shape (rectangle) to an Excel chart:

Sub box2()
'
' box2 Macro
' Macro recorded 1/8/2006 by mk2968
'

'
ActiveChart.Shapes.AddShape(msoShapeRectangle, 13.5, 103#, 59.5, 43#). _
Select
ActiveChart.ChartArea.Select
ActiveChart.Shapes("Rectangle 16").Select
Selection.ShapeRange.ScaleHeight 1#, msoFalse, msoScaleFromBottomRight
ActiveChart.ChartArea.Select
End Sub

What do the '#' characters indicate? I can't find in the documention. Thanks.