anchor.diff:    tomcat8 = throw "tomcat8 has been removed from nixpkgs as it has reached end of life."; # Added 2021-06-16
     tomcat85 = throw "tomcat85 has been removed from nixpkgs as it has reached end of life."; # Added 2020-03-11
     tor-arm = throw "tor-arm has been removed from nixpkgs as the upstream project has been abandoned."; # Added 2022-01-01
  -  torbrowser = tor-browser-bundle-bin; # Added 2017-04-05
  +  torbrowser = throw "'torbrowser' has been renamed to/replaced by 'tor-browser-bundle-bin'"; # Converted to throw 2022-02-22
     torch = throw "torch has been removed, as the upstream project has been abandoned"; # Added 2020-03-28
     torch-hdf5 = throw "torch-hdf5 has been removed, as the upstream project has been abandoned"; # Added 2020-03-28
     torch-repl = throw "torch-repl has been removed, as the upstream project has been abandoned"; # Added 2020-03-28
     torchPackages = throw "torchPackages has been removed, as the upstream project has been abandoned"; # Added 2020-03-28
  -  trang = jing-trang; # Added 2018-04-25
  +  trang = throw "'trang' has been renamed to/replaced by 'jing-trang'"; # Converted to throw 2022-02-22
     transfig = fig2dev; # Added 2022-02-15
     transmission-remote-cli = "transmission-remote-cli has been removed, as the upstream project has been abandoned. Please use tremc instead"; # Added 2020-10-14
  -  transmission_gtk = transmission-gtk; # Added 2018-01-06
  -  transmission_remote_gtk = transmission-remote-gtk; # Added 2018-01-06
  +  transmission_gtk = throw "'transmission_gtk' has been renamed to/replaced by 'transmission-gtk'"; # Converted to throw 2022-02-22
  +  transmission_remote_gtk = throw "'transmission_remote_gtk' has been renamed to/replaced by 'transmission-remote-gtk'"; # Converted to throw 2022-02-22
     transporter = throw "transporter has been removed. It was archived upstream, so it's considered abandoned.";
     trebleshot = throw "trebleshot has been removed. It was archived upstream, so it's considered abandoned.";
     trilium = throw "trilium has been removed. Please use trilium-desktop instead."; # Added 2020-04-29
  -  truecrypt = veracrypt; # Added 2018-10-24
  -  tshark = wireshark-cli; # Added 2018-04-25
  +  truecrypt = throw "'truecrypt' has been renamed to/replaced by 'veracrypt'"; # Converted to throw 2022-02-22
  +  tshark = throw "'tshark' has been renamed to/replaced by 'wireshark-cli'"; # Converted to throw 2022-02-22
     tuijam = throw "tuijam has been removed because Google Play Music was discontinued"; # Added 2021-03-07
     turbo-geth = throw "turbo-geth has been renamed to erigon"; # Added 2021-08-08
     typora = throw "Newer versions of typora use anti-user encryption and refuse to start. As such it has been removed."; # Added 2021-09-11
  
positive.code:   raspberrypi-tools = throw "raspberrypi-tools has been removed in favor of identical 'libraspberrypi'"; # Added 2020-12-24
    rawdog = throw "rawdog has been removed from nixpkgs as it still requires python2."; # Added 2022-01-01
    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
    readline5 = throw "readline-5 is no longer supported in nixpkgs, please use 'readline' for main supported version"; # Added 2022-02-20
    readline62 = throw "readline-6.2 is no longer supported in nixpkgs, please use 'readline' for main supported version"; # Added 2022-02-20
    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
  
negative.code:   # spidermonkey is not ABI upwards-compatible, so only allow this for nix-shell
    spidermonkey = spidermonkey_78; # Added 2020-10-09
    spring-boot = spring-boot-cli; # added 2020-04-24
    sqlite3_analyzer = throw "'sqlite3_analyzer' has been renamed to/replaced by 'sqlite-analyzer'"; # Converted to throw 2022-02-22
    sqliteInteractive = throw "'sqliteInteractive' has been renamed to/replaced by 'sqlite-interactive'"; # Converted to throw 2022-02-22
    squid4 = squid;  # added 2019-08-22
    sshfsFuse = throw "'sshfsFuse' has been renamed to/replaced by 'sshfs-fuse'"; # Converted to throw 2022-02-22
    stanchion = throw "Stanchion was part of riak-cs which is not maintained anymore"; # added 2020-10-14
    stumpwm-git = throw "stumpwm-git has been broken for a long time and lispPackages.stumpwm follows Quicklisp that is close to git version"; # Added 2021-05-09
    subversion19 = throw "subversion19 has been removed as it has reached its end of life"; # Added 2021-03-31
    sundials_3 = throw "sundials_3 was removed in 2020-02. outdated and no longer needed";
    surf-webkit2 = throw "'surf-webkit2' has been renamed to/replaced by 'surf'"; # Converted to throw 2022-02-22
    svgcleaner = throw "svgcleaner has been removed."; # Added 2021-11-17
    swec = throw "swec has been removed; broken and abandoned upstream."; # Added 2021-10-14
    swfdec = throw "swfdec has been removed as broken and unmaintained."; # Added 2020-08-23
    swtpm-tpm2 = swtpm; # Added 2021-02-26
    syncthing-cli = syncthing; # Added 2021-04-06
    synology-drive = throw "synology-drive has been superseded by synology-drive-client"; # Added 2021-11-26
    system_config_printer = throw "'system_config_printer' has been renamed to/replaced by 'system-config-printer'"; # Converted to throw 2022-02-22
    systemd-cryptsetup-generator = throw "systemd-cryptsetup-generator is now included in the systemd package"; # Added 2020-07-12
    systemd_with_lvm2 = throw "systemd_with_lvm2 is obsolete, enabled by default via the lvm module"; # Added 2020-07-12
    systool = throw "'systool' has been renamed to/replaced by 'sysfsutils'"; # Converted to throw 2022-02-22
  
    ### T ###
  
    tahoelafs = throw "'tahoelafs' has been renamed to/replaced by 'tahoe-lafs'"; # Converted to throw 2022-02-22
    tangogps = foxtrotgps; # Added 2020-01-26
    tdm = throw "tdm has been removed because nobody can figure out how to fix OpenAL integration. Use precompiled binary and `steam-run` instead.";
    telepathy-qt = throw "telepathy-qt no longer supports Qt 4. Please use libsForQt5.telepathy instead."; # Added 2020-07-02
    telepathy_farstream = throw "'telepathy_farstream' has been renamed to/replaced by 'telepathy-farstream'"; # Converted to throw 2022-02-22
    telepathy_gabble = throw "'telepathy_gabble' has been renamed to/replaced by 'telepathy-gabble'"; # Converted to throw 2022-02-22
    telepathy_glib = throw "'telepathy_glib' has been renamed to/replaced by 'telepathy-glib'"; # Converted to throw 2022-02-22
    telepathy_haze = throw "'telepathy_haze' has been renamed to/replaced by 'telepathy-haze'"; # Converted to throw 2022-02-22
    telepathy_idle = throw "'telepathy_idle' has been renamed to/replaced by 'telepathy-idle'"; # Converted to throw 2022-02-22
    telepathy_logger = throw "'telepathy_logger' has been renamed to/replaced by 'telepathy-logger'"; # Converted to throw 2022-02-22
    telepathy_mission_control = throw "'telepathy_mission_control' has been renamed to/replaced by 'telepathy-mission-control'"; # Converted to throw 2022-02-22
    telepathy_qt = throw "'telepathy_qt' has been renamed to/replaced by 'telepathy-qt'"; # Converted to throw 2022-02-22
    telepathy_qt5 = throw "'telepathy_qt5' has been renamed to/replaced by 'libsForQt5.telepathy'"; # Converted to throw 2022-02-22
    telepathy_salut = throw "'telepathy_salut' has been renamed to/replaced by 'telepathy-salut'"; # Converted to throw 2022-02-22
    telnet = throw "'telnet' has been renamed to/replaced by 'inetutils'"; # Converted to throw 2022-02-22
    terminus = throw "terminus has been removed, it was unmaintained in nixpkgs"; # Added 2021-08-21
    terraform-provider-ibm = throw "'terraform-provider-ibm' has been renamed to/replaced by 'terraform-providers.ibm'"; # Converted to throw 2022-02-22
    terraform-provider-libvirt = throw "'terraform-provider-libvirt' has been renamed to/replaced by 'terraform-providers.libvirt'"; # Converted to throw 2022-02-22
    terraform-provider-lxd = terraform-providers.lxd; # Added 2020-03-16
    terraform_0_12 = throw "terraform_0_12 has been removed from nixpkgs on 2021/01";
    terraform_1_0 = throw "terraform_1_0 has been renamed to terraform_1"; # Added 2021-12-08
    terraform_1_0_0 = throw "terraform_1_0_0 has been renamed to terraform_1"; # Added 2021-06-15
    tesseract_4 = throw "'tesseract_4' has been renamed to/replaced by 'tesseract4'"; # Converted to throw 2022-02-22
    tex-gyre-bonum-math = throw "'tex-gyre-bonum-math' has been renamed to/replaced by 'tex-gyre-math.bonum'"; # Converted to throw 2022-02-22
    tex-gyre-pagella-math = throw "'tex-gyre-pagella-math' has been renamed to/replaced by 'tex-gyre-math.pagella'"; # Converted to throw 2022-02-22
    tex-gyre-schola-math = throw "'tex-gyre-schola-math' has been renamed to/replaced by 'tex-gyre-math.schola'"; # Converted to throw 2022-02-22
    tex-gyre-termes-math = throw "'tex-gyre-termes-math' has been renamed to/replaced by 'tex-gyre-math.termes'"; # Converted to throw 2022-02-22
    tftp_hpa = throw "'tftp_hpa' has been renamed to/replaced by 'tftp-hpa'"; # Converted to throw 2022-02-22
    thunderbird-68 = throw "Thunderbird 68 reached end of life with its final release 68.12.0 on 2020-08-25.";
    thunderbird-bin-68 = thunderbird-68;
    timescale-prometheus = promscale; # Added 2020-09-29
  