CN implies that the jewellery is produced in China, Whilst the letter D means solitaire diamond, indicating that just one diamond is used in the ring. S925 ALE 54 refers to an international conventional for sterling silver jewellery, in which ALE is brief for Algot Enevoldsen, The daddy of PANDORA, https://casper7732222.answerblogs.com/37130281/little-known-facts-about-jp88