I think I heard [name]Heidi[/name] say on some talkshow that [name]Leni[/name] is [name]Leni[/name]'s full name.
And here she explains that Dashtu is in fact a made up name:
Klum explains, "He has four names and then his last name. My husband is English, but he is from Nigeria originally and they all have a lot of names. So he has one of [name]Seal[/name]'s names, he has one of my father’s names and then he has a funny name that [name]Seal[/name] really liked and then [name]Samuel[/name].
"Dashtu’s the funny one. It is unusual. It is a dash and two, but we write it out, because [name]Seal[/name] really liked it that [name]Henry[/name] goes after our daughter, [name]LENI[/name].
“It’s kind of like a war term, when the first plane goes, there’s always another plane following and it’s called dash two: ‘[name]Dash[/name] two is on course, dash two is following the first place!’ I thought it was really nice so I went with it.”