From 36c1ebd4020dc26c9e82bc969be3e97bb27b5e54 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 15 Oct 2022 19:10:57 -0700
Subject: [PROPOSED 2/5] =?UTF-8?q?Move=20most=20remaining=20links=20to=20?=
 =?UTF-8?q?=E2=80=98backward=E2=80=99?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This simplifies checking and postprocessing a bit.  The sole remaining
link is GMT, as TZUpdater (incorrectly) relies on it being a link
instead of a zone.  The GMT link is in 'backward' only when using
vanguard form.
* checklinks.awk: Simplify due to the link move.
This reverts almost all of the previous change to this file.
---
 africa         |  39 ------------------
 asia           |  16 --------
 australasia    |  10 -----
 backward       | 107 +++++++++++++++++++++++++++++++++++++++++++++++++
 checklinks.awk |  29 ++------------
 europe         |  28 -------------
 northamerica   |  23 -----------
 7 files changed, 110 insertions(+), 142 deletions(-)

diff --git a/africa b/africa
index 7cbd6b0..bd7fe0f 100644
--- a/africa
+++ b/africa
@@ -150,17 +150,6 @@ Zone	Africa/Ndjamena	1:00:12 -	LMT	1912        # N'Djamena
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Abidjan	-0:16:08 -	LMT	1912
 			 0:00	-	GMT
-Link Africa/Abidjan Africa/Accra	# Ghana
-Link Africa/Abidjan Africa/Bamako	# Mali
-Link Africa/Abidjan Africa/Banjul	# The Gambia
-Link Africa/Abidjan Africa/Conakry	# Guinea
-Link Africa/Abidjan Africa/Dakar	# Senegal
-Link Africa/Abidjan Africa/Freetown	# Sierra Leone
-Link Africa/Abidjan Africa/Lome		# Togo
-Link Africa/Abidjan Africa/Nouakchott	# Mauritania
-Link Africa/Abidjan Africa/Ouagadougou	# Burkina Faso
-Link Africa/Abidjan Atlantic/Reykjavik	# Iceland
-Link Africa/Abidjan Atlantic/St_Helena	# St Helena
 
 # Djibouti
 # See Africa/Nairobi.
@@ -448,15 +437,6 @@ Zone	Africa/Nairobi	2:27:16	-	LMT	1908 May
 			2:30	-	+0230	1936 Dec 31 24:00
 			2:45	-	+0245	1942 Jul 31 24:00
 			3:00	-	EAT
-Link Africa/Nairobi Africa/Addis_Ababa	 # Ethiopia
-Link Africa/Nairobi Africa/Asmara	 # Eritrea
-Link Africa/Nairobi Africa/Dar_es_Salaam # Tanzania
-Link Africa/Nairobi Africa/Djibouti
-Link Africa/Nairobi Africa/Kampala	 # Uganda
-Link Africa/Nairobi Africa/Mogadishu	 # Somalia
-Link Africa/Nairobi Indian/Antananarivo	 # Madagascar
-Link Africa/Nairobi Indian/Comoro
-Link Africa/Nairobi Indian/Mayotte
 
 # Lesotho
 # See Africa/Johannesburg.
@@ -1147,14 +1127,6 @@ Zone Africa/El_Aaiun	-0:52:48 -	LMT	1934 Jan # El Aaiún
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Maputo	2:10:20 -	LMT	1903 Mar
 			2:00	-	CAT
-Link Africa/Maputo Africa/Blantyre	# Malawi
-Link Africa/Maputo Africa/Bujumbura	# Burundi
-Link Africa/Maputo Africa/Gaborone	# Botswana
-Link Africa/Maputo Africa/Harare	# Zimbabwe
-Link Africa/Maputo Africa/Kigali	# Rwanda
-Link Africa/Maputo Africa/Lubumbashi	# E Dem. Rep. of Congo
-Link Africa/Maputo Africa/Lusaka	# Zambia
-
 
 # Namibia
 
@@ -1301,15 +1273,6 @@ Zone	Africa/Lagos	0:13:35 -	LMT	1905 Jul  1
 			0:13:35	-	LMT	1914 Jan  1
 			0:30	-	+0030	1919 Sep  1
 			1:00	-	WAT
-Link Africa/Lagos Africa/Bangui		# Central African Republic
-Link Africa/Lagos Africa/Brazzaville	# Rep. of the Congo
-Link Africa/Lagos Africa/Douala		# Cameroon
-Link Africa/Lagos Africa/Kinshasa	# Dem. Rep. of the Congo (west)
-Link Africa/Lagos Africa/Libreville	# Gabon
-Link Africa/Lagos Africa/Luanda		# Angola
-Link Africa/Lagos Africa/Malabo		# Equatorial Guinea
-Link Africa/Lagos Africa/Niamey		# Niger
-Link Africa/Lagos Africa/Porto-Novo	# Benin
 
 # Réunion
 # See Asia/Dubai.
@@ -1375,8 +1338,6 @@ Rule	SA	1943	1944	-	Mar	Sun>=15	2:00	0	-
 Zone Africa/Johannesburg 1:52:00 -	LMT	1892 Feb 8
 			1:30	-	SAST	1903 Mar
 			2:00	SA	SAST
-Link Africa/Johannesburg Africa/Maseru	# Lesotho
-Link Africa/Johannesburg Africa/Mbabane	# Eswatini
 #
 # Marion and Prince Edward Is
 # scientific station since 1947
diff --git a/asia b/asia
index c9bdc4d..e997238 100644
--- a/asia
+++ b/asia
@@ -273,7 +273,6 @@ Zone	Asia/Yangon	6:24:47 -	LMT	1880        # or Rangoon
 			6:30	-	+0630	1942 May
 			9:00	-	+09	1945 May  3
 			6:30	-	+0630
-Link Asia/Yangon Indian/Cocos
 
 # Cambodia
 # See Asia/Bangkok.
@@ -667,8 +666,6 @@ Zone	Asia/Shanghai	8:05:43	-	LMT	1901
 # / Wulumuqi.  (Please use Asia/Shanghai if you prefer Beijing time.)
 Zone	Asia/Urumqi	5:50:20	-	LMT	1928
 			6:00	-	+06
-Link Asia/Urumqi Antarctica/Vostok
-
 
 # Hong Kong
 
@@ -2756,14 +2753,12 @@ Zone Asia/Kuching	7:21:20	-	LMT	1926 Mar
 			8:00 NBorneo  +08/+0820	1942 Feb 16
 			9:00	-	+09	1945 Sep 12
 			8:00	-	+08
-Link Asia/Kuching Asia/Brunei
 
 # Maldives
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Indian/Maldives	4:54:00 -	LMT	1880 # Malé
 			4:54:00	-	MMT	1960 # Malé Mean Time
 			5:00	-	+05
-Link Indian/Maldives Indian/Kerguelen
 
 # Mongolia
 
@@ -3544,7 +3539,6 @@ Zone	Asia/Manila	-15:56:00 -	LMT	1844 Dec 31
 Zone	Asia/Qatar	3:26:08 -	LMT	1920     # Al Dawhah / Doha
 			4:00	-	+04	1972 Jun
 			3:00	-	+03
-Link Asia/Qatar Asia/Bahrain
 
 # Saudi Arabia
 #
@@ -3591,9 +3585,6 @@ Link Asia/Qatar Asia/Bahrain
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Riyadh	3:06:52 -	LMT	1947 Mar 14
 			3:00	-	+03
-Link Asia/Riyadh Antarctica/Syowa
-Link Asia/Riyadh Asia/Aden	# Yemen
-Link Asia/Riyadh Asia/Kuwait
 
 # Singapore
 # taken from Mok Ly Yng (2003-10-30)
@@ -3608,7 +3599,6 @@ Zone	Asia/Singapore	6:55:25 -	LMT	1901 Jan  1
 			9:00	-	+09	1945 Sep 12
 			7:30	-	+0730	1982 Jan  1
 			8:00	-	+08
-Link Asia/Singapore Asia/Kuala_Lumpur
 
 # Spratly Is
 # no information
@@ -3859,9 +3849,6 @@ Zone	Asia/Dushanbe	4:35:12 -	LMT	1924 May  2
 Zone	Asia/Bangkok	6:42:04	-	LMT	1880
 			6:42:04	-	BMT	1920 Apr # Bangkok Mean Time
 			7:00	-	+07
-Link Asia/Bangkok Asia/Phnom_Penh	# Cambodia
-Link Asia/Bangkok Asia/Vientiane	# Laos
-Link Asia/Bangkok Indian/Christmas
 
 # Turkmenistan
 # From Shanks & Pottenger.
@@ -3876,9 +3863,6 @@ Zone	Asia/Ashgabat	3:53:32 -	LMT	1924 May  2 # or Ashkhabad
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Dubai	3:41:12 -	LMT	1920
 			4:00	-	+04
-Link Asia/Dubai Asia/Muscat	# Oman
-Link Asia/Dubai Indian/Mahe
-Link Asia/Dubai Indian/Reunion
 
 # Uzbekistan
 # Byalokoz 1919 says Uzbekistan was 4:27:53.
diff --git a/australasia b/australasia
index d6d1171..f741fbb 100644
--- a/australasia
+++ b/australasia
@@ -466,16 +466,11 @@ Zone	Pacific/Guam	-14:21:00 -	LMT	1844 Dec 31
 			 9:00	-	+09	1944 Jul 31
 			10:00	Guam	G%sT	2000 Dec 23
 			10:00	-	ChST	# Chamorro Standard Time
-Link Pacific/Guam Pacific/Saipan # N Mariana Is
 
 # Kiribati
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Tarawa	 11:32:04 -	LMT	1901 # Bairiki
 			 12:00	-	+12
-Link Pacific/Tarawa Pacific/Funafuti
-Link Pacific/Tarawa Pacific/Majuro
-Link Pacific/Tarawa Pacific/Wake
-Link Pacific/Tarawa Pacific/Wallis
 
 Zone Pacific/Kanton	  0	-	-00	1937 Aug 31
 			-12:00	-	-12	1979 Oct
@@ -573,7 +568,6 @@ Rule	Chatham	2008	max	-	Apr	Sun>=1	2:45s	0	-
 Zone Pacific/Auckland	11:39:04 -	LMT	1868 Nov  2
 			11:30	NZ	NZ%sT	1946 Jan  1
 			12:00	NZ	NZ%sT
-Link Pacific/Auckland Antarctica/McMurdo
 
 Zone Pacific/Chatham	12:13:48 -	LMT	1868 Nov  2
 			12:15	-	+1215	1946 Jan  1
@@ -672,8 +666,6 @@ Zone Pacific/Palau	-15:02:04 -	LMT	1844 Dec 31	# Koror
 Zone Pacific/Port_Moresby 9:48:40 -	LMT	1880
 			9:48:32	-	PMMT	1895 # Port Moresby Mean Time
 			10:00	-	+10
-Link Pacific/Port_Moresby Antarctica/DumontDUrville
-Link Pacific/Port_Moresby Pacific/Chuuk
 #
 # From Paul Eggert (2014-10-13):
 # Base the Bougainville entry on the Arawa-Kieta region, which appears to have
@@ -709,7 +701,6 @@ Zone Pacific/Pitcairn	-8:40:20 -	LMT	1901        # Adamstown
 Zone Pacific/Pago_Pago	 12:37:12 -	LMT	1892 Jul  5
 			-11:22:48 -	LMT	1911
 			-11:00	-	SST	            # S=Samoa
-Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
 
 # Samoa (formerly and also known as Western Samoa)
 
@@ -801,7 +792,6 @@ Zone Pacific/Apia	 12:33:04 -	LMT	1892 Jul  5
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Pacific/Guadalcanal 10:39:48 -	LMT	1912 Oct # Honiara
 			11:00	-	+11
-Link Pacific/Guadalcanal Pacific/Pohnpei
 
 # Tokelau
 #
diff --git a/backward b/backward
index 555e462..cab1e3b 100644
--- a/backward
+++ b/backward
@@ -14,33 +14,97 @@
 # typically use this file for backward compatibility.
 
 # Link	TARGET			LINK-NAME
+Link	Africa/Abidjan		Africa/Accra
+Link	Africa/Nairobi		Africa/Addis_Ababa
+Link	Africa/Nairobi		Africa/Asmara
 Link	Africa/Nairobi		Africa/Asmera
+Link	Africa/Abidjan		Africa/Bamako
+Link	Africa/Lagos		Africa/Bangui
+Link	Africa/Abidjan		Africa/Banjul
+Link	Africa/Maputo		Africa/Blantyre
+Link	Africa/Lagos		Africa/Brazzaville
+Link	Africa/Maputo		Africa/Bujumbura
+Link	Africa/Abidjan		Africa/Conakry
+Link	Africa/Abidjan		Africa/Dakar
+Link	Africa/Nairobi		Africa/Dar_es_Salaam
+Link	Africa/Nairobi		Africa/Djibouti
+Link	Africa/Lagos		Africa/Douala
+Link	Africa/Abidjan		Africa/Freetown
+Link	Africa/Maputo		Africa/Gaborone
+Link	Africa/Maputo		Africa/Harare
+Link	Africa/Nairobi		Africa/Kampala
+Link	Africa/Maputo		Africa/Kigali
+Link	Africa/Lagos		Africa/Kinshasa
+Link	Africa/Lagos		Africa/Libreville
+Link	Africa/Abidjan		Africa/Lome
+Link	Africa/Lagos		Africa/Luanda
+Link	Africa/Maputo		Africa/Lubumbashi
+Link	Africa/Maputo		Africa/Lusaka
+Link	Africa/Lagos		Africa/Malabo
+Link	Africa/Johannesburg	Africa/Maseru
+Link	Africa/Johannesburg	Africa/Mbabane
+Link	Africa/Nairobi		Africa/Mogadishu
+Link	Africa/Lagos		Africa/Niamey
+Link	Africa/Abidjan		Africa/Nouakchott
+Link	Africa/Abidjan		Africa/Ouagadougou
+Link	Africa/Lagos		Africa/Porto-Novo
 Link	Africa/Abidjan		Africa/Timbuktu
+Link	America/Puerto_Rico	America/Anguilla
+Link	America/Puerto_Rico	America/Antigua
 Link	America/Argentina/Catamarca	America/Argentina/ComodRivadavia
+Link	America/Puerto_Rico	America/Aruba
+Link	America/Panama		America/Atikokan
 Link	America/Adak		America/Atka
+Link	America/Puerto_Rico	America/Blanc-Sablon
 Link	America/Argentina/Buenos_Aires	America/Buenos_Aires
 Link	America/Argentina/Catamarca	America/Catamarca
+Link	America/Panama		America/Cayman
 Link	America/Panama		America/Coral_Harbour
 Link	America/Argentina/Cordoba	America/Cordoba
+Link	America/Phoenix		America/Creston
+Link	America/Puerto_Rico	America/Curacao
+Link	America/Puerto_Rico	America/Dominica
 Link	America/Tijuana		America/Ensenada
 Link	America/Indiana/Indianapolis	America/Fort_Wayne
 Link	America/Nuuk		America/Godthab
+Link	America/Puerto_Rico	America/Grenada
+Link	America/Puerto_Rico	America/Guadeloupe
 Link	America/Indiana/Indianapolis	America/Indianapolis
 Link	America/Argentina/Jujuy	America/Jujuy
 Link	America/Indiana/Knox	America/Knox_IN
+Link	America/Puerto_Rico	America/Kralendijk
 Link	America/Kentucky/Louisville	America/Louisville
+Link	America/Puerto_Rico	America/Lower_Princes
+Link	America/Puerto_Rico	America/Marigot
 Link	America/Argentina/Mendoza	America/Mendoza
 Link	America/Toronto		America/Montreal
+Link	America/Puerto_Rico	America/Montserrat
+Link	America/Toronto		America/Nassau
 Link	America/Toronto		America/Nipigon
+Link	America/Puerto_Rico	America/Port_of_Spain
 Link	America/Rio_Branco	America/Porto_Acre
 Link	America/Winnipeg	America/Rainy_River
 Link	America/Argentina/Cordoba	America/Rosario
 Link	America/Tijuana		America/Santa_Isabel
 Link	America/Denver		America/Shiprock
+Link	America/Puerto_Rico	America/St_Barthelemy
+Link	America/Puerto_Rico	America/St_Kitts
+Link	America/Puerto_Rico	America/St_Lucia
+Link	America/Puerto_Rico	America/St_Thomas
+Link	America/Puerto_Rico	America/St_Vincent
 Link	America/Toronto		America/Thunder_Bay
+Link	America/Puerto_Rico	America/Tortola
 Link	America/Puerto_Rico	America/Virgin
+Link	Pacific/Port_Moresby	Antarctica/DumontDUrville
+Link	Pacific/Auckland	Antarctica/McMurdo
 Link	Pacific/Auckland	Antarctica/South_Pole
+Link	Asia/Riyadh		Antarctica/Syowa
+Link	Asia/Urumqi		Antarctica/Vostok
+Link	Europe/Berlin		Arctic/Longyearbyen
+Link	Asia/Riyadh		Asia/Aden
 Link	Asia/Ashgabat		Asia/Ashkhabad
+Link	Asia/Qatar		Asia/Bahrain
+Link	Asia/Kuching		Asia/Brunei
 Link	Asia/Kolkata		Asia/Calcutta
 Link	Asia/Shanghai		Asia/Chongqing
 Link	Asia/Shanghai		Asia/Chungking
@@ -50,15 +114,22 @@ Link	Asia/Shanghai		Asia/Harbin
 Link	Europe/Istanbul		Asia/Istanbul
 Link	Asia/Urumqi		Asia/Kashgar
 Link	Asia/Kathmandu		Asia/Katmandu
+Link	Asia/Singapore		Asia/Kuala_Lumpur
+Link	Asia/Riyadh		Asia/Kuwait
 Link	Asia/Macau		Asia/Macao
+Link	Asia/Dubai		Asia/Muscat
+Link	Asia/Bangkok		Asia/Phnom_Penh
 Link	Asia/Yangon		Asia/Rangoon
 Link	Asia/Ho_Chi_Minh	Asia/Saigon
 Link	Asia/Jerusalem		Asia/Tel_Aviv
 Link	Asia/Thimphu		Asia/Thimbu
 Link	Asia/Makassar		Asia/Ujung_Pandang
 Link	Asia/Ulaanbaatar	Asia/Ulan_Bator
+Link	Asia/Bangkok		Asia/Vientiane
 Link	Atlantic/Faroe		Atlantic/Faeroe
 Link	Europe/Berlin		Atlantic/Jan_Mayen
+Link	Africa/Abidjan		Atlantic/Reykjavik
+Link	Africa/Abidjan		Atlantic/St_Helena
 Link	Australia/Sydney	Australia/ACT
 Link	Australia/Sydney	Australia/Canberra
 Link	Australia/Hobart	Australia/Currie
@@ -106,13 +177,33 @@ Link	Etc/GMT			Etc/Greenwich
 Link	Etc/UTC			Etc/UCT
 Link	Etc/UTC			Etc/Universal
 Link	Etc/UTC			Etc/Zulu
+Link	Europe/Brussels		Europe/Amsterdam
 Link	Europe/London		Europe/Belfast
+Link	Europe/Prague		Europe/Bratislava
+Link	Europe/Zurich		Europe/Busingen
+Link	Europe/Berlin		Europe/Copenhagen
+Link	Europe/London		Europe/Guernsey
+Link	Europe/London		Europe/Isle_of_Man
+Link	Europe/London		Europe/Jersey
 Link	Europe/Kyiv		Europe/Kiev
+Link	Europe/Belgrade		Europe/Ljubljana
+Link	Europe/Brussels		Europe/Luxembourg
+Link	Europe/Helsinki		Europe/Mariehamn
+Link	Europe/Paris		Europe/Monaco
 # Classically, Cyprus is in Asia; e.g. see Herodotus, Histories, I.72.
 # However, for various reasons many users expect to find it under Europe.
 Link	Asia/Nicosia		Europe/Nicosia
+Link	Europe/Berlin		Europe/Oslo
+Link	Europe/Belgrade		Europe/Podgorica
+Link	Europe/Rome		Europe/San_Marino
+Link	Europe/Belgrade		Europe/Sarajevo
+Link	Europe/Belgrade		Europe/Skopje
+Link	Europe/Berlin		Europe/Stockholm
 Link	Europe/Chisinau		Europe/Tiraspol
 Link	Europe/Kyiv		Europe/Uzhgorod
+Link	Europe/Zurich		Europe/Vaduz
+Link	Europe/Rome		Europe/Vatican
+Link	Europe/Belgrade		Europe/Zagreb
 Link	Europe/Kyiv		Europe/Zaporozhye
 Link	Europe/London		GB
 Link	Europe/London		GB-Eire
@@ -129,6 +220,14 @@ Link	Etc/GMT			Greenwich
 # End of rearguard section.
 Link	Asia/Hong_Kong		Hongkong
 Link	Africa/Abidjan		Iceland
+Link	Africa/Nairobi		Indian/Antananarivo
+Link	Asia/Bangkok		Indian/Christmas
+Link	Asia/Yangon		Indian/Cocos
+Link	Africa/Nairobi		Indian/Comoro
+Link	Indian/Maldives		Indian/Kerguelen
+Link	Asia/Dubai		Indian/Mahe
+Link	Africa/Nairobi		Indian/Mayotte
+Link	Asia/Dubai		Indian/Reunion
 Link	Asia/Tehran		Iran
 Link	Asia/Jerusalem		Israel
 Link	America/Jamaica		Jamaica
@@ -142,11 +241,19 @@ Link	Pacific/Auckland	NZ
 Link	Pacific/Chatham		NZ-CHAT
 Link	America/Denver		Navajo
 Link	Asia/Shanghai		PRC
+Link	Pacific/Port_Moresby	Pacific/Chuuk
 Link	Pacific/Kanton		Pacific/Enderbury
+Link	Pacific/Tarawa		Pacific/Funafuti
 Link	Pacific/Honolulu	Pacific/Johnston
+Link	Pacific/Tarawa		Pacific/Majuro
+Link	Pacific/Pago_Pago	Pacific/Midway
+Link	Pacific/Guadalcanal	Pacific/Pohnpei
 Link	Pacific/Guadalcanal	Pacific/Ponape
+Link	Pacific/Guam		Pacific/Saipan
 Link	Pacific/Pago_Pago	Pacific/Samoa
 Link	Pacific/Port_Moresby	Pacific/Truk
+Link	Pacific/Tarawa		Pacific/Wake
+Link	Pacific/Tarawa		Pacific/Wallis
 Link	Pacific/Port_Moresby	Pacific/Yap
 Link	Europe/Warsaw		Poland
 Link	Europe/Lisbon		Portugal
diff --git a/checklinks.awk b/checklinks.awk
index 45f67e3..b2bb17a 100644
--- a/checklinks.awk
+++ b/checklinks.awk
@@ -7,18 +7,6 @@ BEGIN {
     # It is a newline so that it cannot match a valid name.
     # It is not null so that its slot does not appear unset.
     Zone = "\n"
-
-    if (!zone_table) zone_table = "zone.tab"
-
-    while (getline <zone_table) {
-	if (/^#/) continue
-	zone_cc[$3] = $1
-    }
-
-    # As a special case, a link to "GMT" is allowed in a continental file.
-    # Remove this special case once the hack for TZUpdater 2.3.2 is
-    # moved from main to reaguard form.
-    zone_cc["GMT"] = 1
 }
 
 /^Z/ {
@@ -31,7 +19,6 @@ BEGIN {
 	status = 1
     }
     defined[$2] = Zone
-    last_zone = $2
 }
 
 /^L/ {
@@ -45,19 +32,9 @@ BEGIN {
 	}
 	status = 1
     }
-    if (backcheck) {
-	backward = FILENAME == backcheck
-	if (!!zone_cc[$3] == backward) {
-	    shouldbe = backward ? "a continental file" : "'backward'"
-	    printf "%s:%d: %s: Link should be in %s\n", \
-		FILENAME, FNR, $3, shouldbe
-	    status = 1
-	}
-	if (!backward && $2 != last_zone) {
-	    printf "%s:%d: Link %s should come just after Zone %s\n", \
-		FILENAME, FNR, $3, $2
-	    status = 1
-	}
+    if (backcheck && FILENAME != backcheck && $3 != "GMT") {
+      printf "%s: Link should be in '%s'\n", $3, backcheck
+      status = 1
     }
     used[$2] = 1
     defined[$3] = $2
diff --git a/europe b/europe
index af382c9..9621229 100644
--- a/europe
+++ b/europe
@@ -504,9 +504,6 @@ Zone	Europe/London	-0:01:15 -	LMT	1847 Dec  1
 			 1:00	-	BST	1971 Oct 31  2:00u
 			 0:00	GB-Eire	%s	1996
 			 0:00	EU	GMT/BST
-Link	Europe/London	Europe/Jersey
-Link	Europe/London	Europe/Guernsey
-Link	Europe/London	Europe/Isle_of_Man
 
 # From Paul Eggert (2018-02-15):
 # In January 2018 we discovered that the negative SAVE values in the
@@ -961,8 +958,6 @@ Zone	Europe/Brussels	0:17:30 -	LMT	1880
 			1:00	C-Eur	CE%sT	1944 Sep  3
 			1:00	Belgium	CE%sT	1977
 			1:00	EU	CE%sT
-Link Europe/Brussels Europe/Amsterdam
-Link Europe/Brussels Europe/Luxembourg
 
 # Bosnia and Herzegovina
 # See Europe/Belgrade.
@@ -1025,8 +1020,6 @@ Zone	Europe/Prague	0:57:44 -	LMT	1850
 # End of rearguard section.
 			1:00	Czech	CE%sT	1979
 			1:00	EU	CE%sT
-Link Europe/Prague Europe/Bratislava
-
 
 # Denmark, Faroe Islands, and Greenland
 # For Denmark see Europe/Berlin.
@@ -1259,10 +1252,6 @@ Zone	Europe/Helsinki	1:39:49 -	LMT	1878 May 31
 			2:00	Finland	EE%sT	1983
 			2:00	EU	EE%sT
 
-# Åland Is
-Link	Europe/Helsinki	Europe/Mariehamn
-
-
 # France
 
 # From Ciro Discepolo (2000-12-20):
@@ -1400,7 +1389,6 @@ Zone	Europe/Paris	0:09:21 -	LMT	1891 Mar 16
 			0:00	France	WE%sT	1945 Sep 16  3:00
 			1:00	France	CE%sT	1977
 			1:00	EU	CE%sT
-Link Europe/Paris Europe/Monaco
 
 # Germany
 
@@ -1444,11 +1432,6 @@ Zone	Europe/Berlin	0:53:28 -	LMT	1893 Apr
 			1:00 SovietZone	CE%sT	1946
 			1:00	Germany	CE%sT	1980
 			1:00	EU	CE%sT
-Link Europe/Berlin Arctic/Longyearbyen
-Link Europe/Berlin Europe/Copenhagen
-Link Europe/Berlin Europe/Oslo
-Link Europe/Berlin Europe/Stockholm
-
 
 # Georgia
 # Please see the "asia" file for Asia/Tbilisi.
@@ -1689,9 +1672,6 @@ Zone	Europe/Rome	0:49:56 -	LMT	1866 Dec 12
 			1:00	C-Eur	CE%sT	1944 Jun  4
 			1:00	Italy	CE%sT	1980
 			1:00	EU	CE%sT
-Link Europe/Rome Europe/Vatican
-Link Europe/Rome Europe/San_Marino
-
 
 # Kosovo
 # See Europe/Belgrade.
@@ -3294,11 +3274,6 @@ Zone	Europe/Belgrade	1:22:00	-	LMT	1884
 # Shanks & Pottenger don't give as much detail, so go with Koželj.
 			1:00	-	CET	1982 Nov 27
 			1:00	EU	CE%sT
-Link Europe/Belgrade Europe/Ljubljana	# Slovenia
-Link Europe/Belgrade Europe/Podgorica	# Montenegro
-Link Europe/Belgrade Europe/Sarajevo	# Bosnia and Herzegovina
-Link Europe/Belgrade Europe/Skopje	# North Macedonia
-Link Europe/Belgrade Europe/Zagreb	# Croatia
 
 # Slovakia
 # See Europe/Prague.
@@ -3527,9 +3502,6 @@ Zone	Europe/Zurich	0:34:08 -	LMT	1853 Jul 16 # See above comment.
 			0:29:46	-	BMT	1894 Jun    # Bern Mean Time
 			1:00	Swiss	CE%sT	1981
 			1:00	EU	CE%sT
-Link Europe/Zurich Europe/Busingen
-Link Europe/Zurich Europe/Vaduz
-
 
 # Turkey
 
diff --git a/northamerica b/northamerica
index 1041915..495c2dc 100644
--- a/northamerica
+++ b/northamerica
@@ -829,7 +829,6 @@ Zone America/Phoenix	-7:28:18 -	LMT	1883 Nov 18 19:00u
 			-7:00	-	MST	1967
 			-7:00	US	M%sT	1968 Mar 21
 			-7:00	-	MST
-Link America/Phoenix America/Creston
 
 # From Arthur David Olson (1988-02-13):
 # A writer from the Inter Tribal Council of Arizona, Inc.,
@@ -1720,7 +1719,6 @@ Zone America/Toronto	-5:17:32 -	LMT	1895
 			-5:00	Canada	E%sT	1946
 			-5:00	Toronto	E%sT	1974
 			-5:00	Canada	E%sT
-Link America/Toronto America/Nassau
 # For Atikokan see America/Panama.
 
 
@@ -3499,8 +3497,6 @@ Zone	America/Managua	-5:45:08 -	LMT	1890
 Zone	America/Panama	-5:18:08 -	LMT	1890
 			-5:19:36 -	CMT	1908 Apr 22 # Colón Mean Time
 			-5:00	-	EST
-Link America/Panama America/Atikokan
-Link America/Panama America/Cayman
 
 # Puerto Rico
 # There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
@@ -3509,25 +3505,6 @@ Zone America/Puerto_Rico -4:24:25 -	LMT	1899 Mar 28 12:00 # San Juan
 			-4:00	-	AST	1942 May  3
 			-4:00	US	A%sT	1946
 			-4:00	-	AST
-Link America/Puerto_Rico America/Anguilla
-Link America/Puerto_Rico America/Antigua
-Link America/Puerto_Rico America/Aruba
-Link America/Puerto_Rico America/Curacao
-Link America/Puerto_Rico America/Blanc-Sablon	# Quebec (Lower North Shore)
-Link America/Puerto_Rico America/Dominica
-Link America/Puerto_Rico America/Grenada
-Link America/Puerto_Rico America/Guadeloupe
-Link America/Puerto_Rico America/Kralendijk	# Caribbean Netherlands
-Link America/Puerto_Rico America/Lower_Princes	# Sint Maarten
-Link America/Puerto_Rico America/Marigot	# St Martin (French part)
-Link America/Puerto_Rico America/Montserrat
-Link America/Puerto_Rico America/Port_of_Spain	# Trinidad & Tobago
-Link America/Puerto_Rico America/St_Barthelemy	# St Barthélemy
-Link America/Puerto_Rico America/St_Kitts	# St Kitts & Nevis
-Link America/Puerto_Rico America/St_Lucia
-Link America/Puerto_Rico America/St_Thomas	# Virgin Islands (US)
-Link America/Puerto_Rico America/St_Vincent
-Link America/Puerto_Rico America/Tortola	# Virgin Islands (UK)
 
 # St Kitts-Nevis
 # St Lucia
-- 
2.37.3