The True Naming

Eltari hold names in a special regard as something that should be chosen by none other than the individual who bears it, for if you are to be recognised in the world around you as anything, that thing should be yours to determine. As such, it is tradition that when an Eltari comes of age through deed and accomplishment, they choose their true name that they will henceforth be known by in place of their given name.

History

This tradition hails back to the end of the Eltari Uprising, where the six generals fought and defeated the kalydrid emperor, and declaring themselves to the galaxy by their new names, their true names, not the ones given to them as slaves. With their newfound freedom, the Eltari chose themselves names that better represented them than those they had been given, and intended to continue forward not giving names to the future generations themselves that they may choose their own as of their volition.
In practice, this had to be adjusted somewhat after encountering the logistical issues of having no names to call their young by, and in the cases where the young chose names they would often wish to change them at a whim, leading to further issues with trying to maintain this system. As such, a new one was adapted in part to maintain some semblance of order, as well as serving as a reminder of eltari history: guardians would name their youth as the slave masters of old once did, though would use it sparingly. Then, once the youth had matured and achieved some level of accomplishment to prove their ability to stand on their own as an individual, they would have their guardianship relinquished, and a naming ceremony given where they would announce their true name to their friends and loved ones before having their given name scrubbed and replaced from all records, forgotten to the ages.
This wasn't completely flawless, as sometimes the guardians would die or become separated from their youth, making it impossible to grant them the ceremony, and so academic institutes and certain professions were granted limited power to perform the true naming themselves on graduation or equivalent recognition. Sometimes the individual grew particularly fond of their given name and wished to keep it, despite this being frowned upon and leading to stigmatisation. Finally, there was the matter of surname. When the tradition started, there were few enough eltari for it to be irrelevant, but as more and more wished for the same name, some form of further convention was needed to reduce confusion. As eltari didn't produce offspring naturally, it felt more fitting to not bind such a thing to other eltari directly, but through some measure of devotion or area, especially within academic fields. 
Over time, as the generations grew more distant from the slavery they had once endured, the given name became less of a taboo and gained a more intimate standing in society, where rather than being truly forgotten, it remained as a sign of trust and respect to be given out to those who you'd trust with your life.