anchor.diff:    s6PortableUtils = s6-portable-utils; # added 2018-07-23
     sagemath = sage; # added 2018-10-27
     sam = deadpixi-sam; # added 2018-04-25
  -  samba3 = throw "Samba 3 is discontinued, please switch to samba4"; # added 2019-10-15
  -  samba3_light = throw "Samba 3 is discontinued, please switch to samba4"; # added 2019-10-15
  -  sambaMaster = throw "sambaMaster was removed in 2019-09-13: outdated and no longer needed";
     samsungUnifiedLinuxDriver = samsung-unified-linux-driver; # added 2016-01-25
     saneBackends = sane-backends; # added 2016-01-02
     saneBackendsGit = sane-backends; # added 2016-01-02
     sane-backends-git = sane-backends; # added 2021-02-19
     saneFrontends = sane-frontends; # added 2016-01-02
  -  sapic = throw "sapic was deprecated on 2019-1-19: sapic is bundled with 'tamarin-prover' now";
     scaff = throw "scaff is deprecated - replaced by https://gitlab.com/jD91mZM2/inc (not in nixpkgs yet)"; # added 2020-03-01
     scim = sc-im; # added 2016-01-22
     scollector = bosun; # added 2018-04-25
  
positive.code:   qwt6 = libsForQt5.qwt;  # added 2015-12-19
    qtkeychain = throw "the qtkeychain attribute (qt4 version) has been removes, use the qt5 version: libsForQt5.qtkeychain"; # added 2021-08-04
    qtcurve = libsForQt5.qtcurve;  # added 2020-11-07
    qtpfsgui = throw "qtpfsgui is now luminanceHDR"; # added 2019-06-26
    quaternion-git = throw "quaternion-git has been removed in favor of the stable version 'quaternion'"; # added 2020-04-09
    raspberrypi-tools = throw "raspberrypi-tools has been removed in favor of identical 'libraspberrypi'"; # added 2020-12-24
    rdf4store = throw "rdf4store has been removed from nixpkgs."; # added 2019-12-21
    rdiff_backup = rdiff-backup;  # added 2014-11-23
    rdmd = dtools;  # added 2017-08-19
    readline80 = throw "readline-8.0 is no longer supported in nixpkgs, please use 'readline' for main supported version or 'readline81' for most recent version"; # added 2021-04-22
    rhc = throw "rhc was deprecated on 2019-04-09: abandoned by upstream.";
    rng_tools = rng-tools; # added 2018-10-24
    robomongo = robo3t; #added 2017-09-28
    rocm-runtime-ext = throw "rocm-runtime-ext has been removed, since its functionality was added to rocm-runtime"; #added 2020-08-21
  
negative.code:   bomi = throw "bomi has been removed from nixpkgs since it was broken and abandoned upstream"; # added 2020-12-10
    btrfsProgs = btrfs-progs; # added 2016-01-03
    bitsnbots = throw "bitsnbots has been removed because it was broken and upstream missing"; # added 2021-08-22
  
    # bitwarden_rs renamed to vaultwarden with release 1.21.0 (2021-04-30)
    bitwarden_rs = vaultwarden;
  