Package check result: NOTE

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Tamás Stirling <stirling.tamas@gmail.com>’
  
  Found the following (possibly) invalid URLs:
    URL: https://webbook.nist.gov/chemistry/gc-ri/
      From: man/nist_ri.Rd
      Status: 522
    URL: https://www.chemspider.com/
      From: man/cs_extcompinfo.Rd
      Status: 403
      Message: Forbidden

No changes to worse in reverse depends.