what is the importance of naming and the not mentioning of names in the story?
Additionally, the naming of some characters could be significant such as Jack, who would be rather be called by his last name as was common for adults or school boys - rather than Jack which is what a kid would be called.
Also, Percival Wemys Madison is the name of a little one and he has been taught to recite his full name and address in the case that he should get lost. In the situation, this is exactly what he does which reminds everyone that the boys are indeed lost.
The significance of the name Ralph is lost on modern readers but Golding intended the reader to be reminded of a character in a then popular children's tale by R. M. Ballantyne.
Simon's name is the most symbolically referenced as it refers to Saint Simon. Simon in the story is the only one who sees things as they are and tries to warn the boys.
Sameneric is the name for the twins who cannot be separate from each other. They do not exist as two individuals but as one.
You have some great answers here, but it is also interesting to note that Piggy's nickname also refers to the wild pigs on the island...which are hunted and killed both for fun and for food. Piggy also proves useful as a source of reason and fire--his glasses--until his usefulness is no more (Jack and the others steal Piggy's glasses) and he is murdered.