Package check result: NOTE

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Nikolaus Umlauf <Nikolaus.Umlauf@uibk.ac.at>’
  
  Found the following (possibly) invalid URLs:
    URL: https://www.acm.org/publications/policies/software-copyright-notice
      From: man/plot3d.Rd
            man/sliceplot.Rd
      Status: 403
      Message: Forbidden

No changes to worse in reverse depends.