Voldemort hänvisar till sig själv i den tredje personen (aldrig ett gott tecken, undvik människor som gör det) som "Lord Voldemort":
Harry’s voice was high, clear, and cold, his wand held in front of him by a long-fingered white hand. The man at whom he was pointing was suspended upside down in midair... “I have it not, I have it no more! It was, many years ago, stolen from me!” “Do not lie to Lord Voldemort, Gregorovitch. He knows. . . . He always knows.” ~Harry Potter and the Deathly Hallows - The Thief
Hans anhängare, sympatisörer (och Snape) hänvisar till honom som "den mörka herren" när han talar om honom och i sin närvaro adresserar de honom som "min herre"
“My Lord,” Yaxley went on, “Dawlish believes an entire party of Aurors will be used to transfer the boy —”~Harry Potter and the Deathly Hallows - The Dark Lord Ascending
Bellatrix är den som protesterar när Harry kallar honom "Voldemort":
“Shut your mouth!” Bellatrix shrieked. “You dare speak his name with your unworthy lips, you dare besmirch it with your half-blood’s tongue, you dare—” ~Order of the Phoenix, chapter 35 -Beyond the Veil
De människor som kämpade honom, som Dumbledore och Harry, kallar honom "Tom" eller "Riddle" i hans ansikte, (som han hatar som det här namnet representerar sin mugglefader) och "Voldemort" när han inte är närvarande:
“So, Tom . . . to what do I owe the pleasure?” Voldemort did not answer at once, but merely sipped his wine. “They do not call me ‘Tom’ anymore,” he said. “These days, I am known as —” “I know what you are known as,” said Dumbledore, smiling pleasantly. “But to me, I’m afraid, you will always be Tom Riddle. ~Harry Potter and the Half-Blood Prince- Lord Voldemort's Request
och Harry i sista striden:
I’ve done what my mother did. They’re protected from you. Haven’t you noticed how none of the spells you put on them are binding? You can’t torture them. You can’t touch them. You don’t learn from your mistakes, Riddle, do you?” “You dare —” “Yes, I dare,” said Harry. “I know things you don’t know, Tom Riddle. I know lots of important things that you don’t. Want to hear some, before you make another big mistake? ~Harry Potter and the Deathly Hallows -The Flaw in the Plan
Andra beställande medlemmar kallar också honom Voldemort. Alla andra kallar honom "You-Know-Who" eller "He-Who-Must-Not-Be-Named". Som det enda folket vågar kalla honom "Voldemort" var de som kämpade honom, använde han en stavning för att spåra människor med det:
“but the name’s been jinxed, Harry, that’s how they track people! Using his name breaks protective enchantments, it causes some kind of magical disturbance — it’s how they found us in Tottenham Court Road!” “Because we used his name?” “Exactly! You’ve got to give them credit, it makes sense. It was only people who were serious about standing up to him, like Dumbledore, who ever dared use it. Now they’ve put a Taboo on it, anyone who says it is trackable — quick-and-easy way to find Order members! They nearly got Kingsley — ~Harry Potter and the Deathly Hallows - Xenophilius Lovegood
Men det betyder inte att han utsätter människor som uttrycker sig för namnet "Voldemort". Han verkar inte ha problem med det:
How did you escape with nothing but a scar, while Lord Voldemort’s powers were destroyed?” There was an odd red gleam in his hungry eyes now. “Why do you care how I escaped?” said Harry slowly. “Voldemort was after your time. . . .” “Voldemort,” said Riddle softly, “ is my past, present, and future, Harry Potter. . . .” ~Harry Potter and the Chamber of Secrets - The Heir of Slytherin
Jag är inte en stor fan av det förbannade barnet, men den scen du refererar till händer i ett dystopiskt samhälle där Voldemort hade vunnit. Människor skulle idolera honom så "du-vet-vem" är ur frågan. Det finns ingen konflikt med mörk mot ljus längre, så ingen anledning kallar honom "Dark Lord".
"För Voldemort och Valor" är en catchy alliteration, så förmodligen blev killen Voldemort ansvarig för PR upp med det och det påminner både om Mao, Stalin och Kim Il som sjungit sin personlighetskult och hälsningen i tredje Reich, så det verkar övertygande och passande med tanke på situationen.