The Elven Ritual of Passage
From the times before the Scourge, the Ritual of Passage consisted of a two step process, the first taking place seven days before the elf's twentieth birthday and the second on the actual day. As the Rite of Pronouncement changed during the Scourge, so did this.
Some places still hold to the old ways and have not changed either ritual. Those places were fortunate. Now, the Ritual of Passage still takes place in two steps, but not as close together as seven days.
Before the first stage can occur, the young elf must decide if his parents or guardians chose his name well. If the elf decides they have, then he proceeds to study what he wishes to become. With the dangers of the world as they are, the elf starts life young, especially if he feels the tingle of magic in him. If the elf decides they have not, he chooses a new first name and then begins to follow his path.
At the time of the elf's twentieth birthday, the elf may choose to continue his Passage. If his is happy with his path and chooses to continue it, the elf may take a second name, without changing his first name, to symbolize the change from his youth to complete adulthood. Otherwise, the elf may take a completely new name and change his path in life.
Sa'mistishsa elves favor the changing of names, as they are strict followers of the wheel of life. Dae'mistishsa elves favor the addition of names to symbolize change because the change in one's path is only known by the elf himself and the change in the path may not completely change the elf.
With Regards to Patterns
When a person is re-Named, their true pattern changes and alters much of what he used to be. Everything that they were is now gone, including disciplines and talents. However, if a person takes a second name (or earns a second name or title etc.), this is not re-Naming, only an addition to the person's ever changing pattern. It does not change who they were any more than adding a discipline changes who they were.