I recently came across this section of code and was wondering what these variables represent?

Sub Demo1()
  Const F = "IF(ISNUMBER(Q#:U#),IF(MONTH(Q#:U#)=MONTH(I#),ADDRESS(#,COLUMN(Q#:U#))))"
    Dim L&, R&, V
        L = UsedRange.Rows.Count
        Application.ScreenUpdating = False
        Range("I2:I" & L & ",Q2:U" & L).Interior.ColorIndex = xlNone
    For R = 2 To L
        V = Filter(Evaluate(Replace(F, "#", R)), False, False)
        If UBound(V) > -1 Then Range("I" & R & "," & Join(V, ",")).Interior.ColorIndex = 6
    Next
       Application.ScreenUpdating = True
End Sub
The code works as intended ( highlights all dates within the range Q, R, S, T &U to last row, that matches (same month) of a date in Column I.

I am curious about the L&, R& designations