The following code should produce "nan" but on assignment of a const nan float it defaults to "0".

class TAG_Const
{
	const float FloatNan = "nan".ToFloat();
}
float test = TAG_Const.FloatNan;

SCRIPT : float test = 0

Using the right-hand side assignment with the instructions to build nan directly however works.

float test = "nan".ToFloat();

SCRIPT : float test = nan

It also works when using a non const variant.

class TAG_Static
{
	static float FloatNan = "nan".ToFloat();
}
float test = TAG_Static.FloatNan;

SCRIPT : float test = nan

However even when only using static, it fails as a default function parameter

void testfnc(float test = TAG_Static.FloatNan)
{
	Print(test);
}

SCRIPT : float test = 0