where 3 countries meet

the revised
iso coded
official united nations tripoint registry
& yearbook
currently acknowledges 176 territorial trijunctions of member states

most of these occur at
& are
simple definitely agreed tripoints

but a few are indefinite or disputed
or still only notional territorial conjunctions

& in rare cases of territorial overlap or condominium
some few trijunctions do not produce simple tricountry points
but rather take the form of tricountry lines
or trilines
& even a couple of tricountry areas
or triareas

the great majority of the trijunctions are continental or inland
tho most of these are actually situated in lakes & rivers
while a few others are maritime

most trijunctions are single or singular
but a few are coupled or twinned

all 176 can be most simply & concisely expressed in codes of 6 or 7 letters that arrange alphabetically the 3 iso country code digraphs of the component member states
& sometimes add a directional suffix
to distinguish the couples both from each other & from the singles

iso coder
http://www.iso.org/iso/english_country_names_and_code_elements
& decoder
http://www.iso.org/iso/country_codes/iso_3166_code_lists/iso-3166-1_decoding_table.htm

thus adesfre for example is the more easterly of the twin tripoints of andorra with spain & france
& its westerly twin is adesfrw
etc

the full set of the 176 tricountry points & lines & areas at the moment
also known as the world class
is as follows

adesfre
adesfrw
aeomsa
aeqasa
afcnpk
afcntj
afirpk
afirtm
aftjuz
aftmuz 10

algrmk
almers
almkrs
amazge
amazire
amazirw
amaztr
amgetr
aocdcg
aocdzm 20

aonazm
arbocl
arbopy
arbrpy
arbruy
atchde
atchit
atchlin
atchlis
atczde 30

atczsk
athusi
athusk
atitsi
azgeru
azirtm
azirtr
azkzru
azkztm
bahrme 40

bahrrs
bamers
bdinmm
bedelu
bedenl
befrlu
bfbjne
bfbjtg
bfcigh
bfciml 50

bfghtg
bfmlne
bggrmk
bggrtr
bgmkrs
bgrors
bhqasa
bicdrw
bicdtz
birwtz 60

bjneng
bobrpe
bobrpy
boclpe
brcope
brcove
brfrsr
brgysr
brgyve
btcnine 70

btcninw
bwnaza
bwnazm
bwzazw
bwzmzw
byltlv
byltpl
bylvru
byplua
byruua 80

bzgthn
bzgtmx
cdcfcg
cdcfsd
cdrwug
cdsdug
cdtzzm
cfcgcm
cfcmtd
cfsdtd 90

cgcmga
chdefr
chfrit
cignlr
cignml
cmgagq
cmngtd
cninmm
cninnpe
cninnpw 100

cninpk
cnkgkz
cnkgtj
cnkpru
cnkzru
cnlamm
cnlavn
cnmnrue
cnmnruw
coecpe 110

czdepl
czplsk
defrlu
djeret
djerye
djetso
dzlyne
dzlytn
dzmamr
dzmlmr 120

dzmlne
eelvru
egiljo
egjosa
eglysd
eretsd
etkesd
etkeso
finoru
finose 130

gngwsn
gnlrsl
gnmlsn
gthnsv
hnnisve
hnnisvw
hrhurs
hrhusi
hritsi
hurors 140

huroua
huskua
idmysge
idmysgw
iljosy
illbsy
iqirtr
iqjosa
iqjosy
iqkwsa 150

iqsytr
kesdug
ketzug
kgkzuz
kgtjuz
khlath
khlavn
kztmuz
lammth
ltplru 160

lynetd
lysdtd
mdrouan
mdrouas
mlmrsn
mwmztz
mwmzzm
mwtzzm
mzszzan
mzszzas 170

mzzazw
mzzmzw
nengtd
omsaye
plskua
rwtzug 176