Which of the following addresses are identical to each other:
1. S. lyer 17-D, Coral Residency, Thiruvananthapuram, 695014
2. S. lyer 17-D, Coral Residency, Thiruvananthapuram, 695014
3. S. lyer 17-D Coral Residency, Thiruvananthapuram, 695014
4. S. Iyer 17-D Coral Residency, Thiruvananthapuram, 695013

The correct option is 1 and 2.

To determine which of the given addresses are completely identical, let us perform a detailed character-by-character comparison of each address provided in the question:

1. S. lyer 17-D, Coral Residency, Thiruvananthapuram, 695014
2. S. lyer 17-D, Coral Residency, Thiruvananthapuram, 695014
3. S. lyer 17-D Coral Residency, Thiruvananthapuram, 695014
4. S. Iyer 17-D Coral Residency, Thiruvananthapuram, 695013

Let us analyze the differences across the options:
- Address 1 and Address 2 match exactly in every character, punctuation mark (comma after '17-D'), and PIN code (695014).
- Address 3 is missing a comma after "17-D" (it reads "17-D Coral Residency" instead of "17-D, Coral Residency").
- Address 4 uses a capital 'I' in "Iyer" instead of lowercase 'l' in "lyer", is missing the comma after "17-D", and has a different PIN code (695013 instead of 695014).

Therefore, address 1 and address 2 are identical to each other.