Ah yes, Xarx-Zero, pronounced “Alex-Zero”, with the Zero Gundam. Not to be confused with:

-0 Gundam (pronounced oh)

-00 Gundam

-The O

-Wing Gundam Zero

-Gundam Alex

And this is part of the RG Project, not to be confused with RG (Real Grade) model kits! My guess is the designers were discussing over beers how confusing they could make the naming scheme and still have the execs sign off on it.