Distinguished country pairs

I guess that everybody here at puzzling.stackexchange is aware of the fact that Uzbekhistan and Liechtenstein are the only two countries in the world that are doubly landlocked and hence share a very distinguished property.

The following list shows parts of some other country pairs that share very distinguished properties .(the properties are natural; no loopholes; no trick solutions).

1. Italy and S????? are the only two countries that have property A.
2. Switzerland and V????? are the only two countries that have property B.
3. Ethiopia and L1???? are the only two countries that have property C.
4. Saudi Arabia and L2???? are the only two countries that have property D.
5. Mexico and L3???? are the only two countries that have property E.
6. Ireland and N????? are the only two countries that have property F.

Solve for the six countries S?????, V?????, L1????, L2????, L3????, N????? (with the given initial letter) and the six properties $A, B, C, D, E, F$.

• Can we assume all of the properties are of geographical nature? Or rather, don't apply to silly things like the country name? (In short: What does natural mean?) - Also this seems way too broad in general, I'm afraid. Feb 23, 2015 at 10:42
• Could you improve on your definition of "natural"? I'm assuming 2 is not something like "Switzerland and Vatican City have a square flag", right?
– dmg
Feb 23, 2015 at 11:48
• Answer 1 from skifans, answers 3 and 4 from Gamov, answers 2, 5, 6 from Haobin. The prize goes to Haobin. Feb 24, 2015 at 19:34
• I find it funny that both me and @dmg were pretty much spot on for one of the properties. Also the country name one only works with all English names. Feb 25, 2015 at 7:28

• For number 2: Switzerland and Vatican are the only countries whose flag is square-shaped.

• For number 5, I would guess: Mexico and Luxembourg are the only countries on Earth whose name contains the letter X.
This is a very distinguished property: all other letters occur multiple times. The rare letters are J, K, Q, X and Y. But for J there are Japan, Azerbaijan, Jamaica, Jordan, Tajikistan, etc. For K there are Kazakhstan, Kenya, Korea, Kuwait, Pakistan, Turkey, Sri Lanka, etc. For Q there are Qatar, Iraq, Equatorial Guinea, Martinique, Mozambique. For Y there are Yemen, Germany, Hungary, Turkey, Cyprus, Egypt, Guyana, Kenya, etc. For X there are only two.

• I remember the answer to number 6 from the "Trivial Pursuit" quiz game. Ireland and New Zealand are the only two countries in the world that lack native snakes.

• And that's why we celebrate St. Patrick's Day! Feb 23, 2015 at 17:20

Question 3:
According to that [webpage]: Liberia and Ethiopia are the only two African countries that have never been colonized ("which are considered to have survived the scramble for Africa and remained independent during the invasion, partitioning and forceful ruling of Africa by European nations")

Question 4:
According to that [book]: Liechtenstein and Saudi Arabia are the only two countries in the world whose names are associated with the ruling family.

Having a bit of a guess at 6,

Ireland and The UK are the only countries on Great Britain

Just had an idea for 1

Italy and South Africa are the only countries which totally surround other countries.

And 5

Mexico and Canada are the only countries who have a land border with the USA.

• I would not call it a "very distinguished property" that Mexico and Canada have a land border with the USA. There are dozens of other country groups with analogous properties (Norway and Finland are the only countries who have a land border with Sweden; etc.) Feb 23, 2015 at 12:23
• The edit with first letters show that your guesses for 5 and 6 are incorrect, probably for the reason that @Gamow gives. Feb 23, 2015 at 17:19
• You disrespect the first letter requirements! Apr 20, 2016 at 20:16
• @user69715 the first letters had not yet been disclosed when this answer was posted. Mar 21, 2018 at 22:21