Ok this question specifically concerns DigiBen''s Octree class (gametutorials.com octree2 program). In his program when he creates a new node, the function looks like this:

oid COctree::CreateNewNode(CPoly *pPoly, vector<bool> pList, int numberOfVerts,
					  	    CVector3 vCenter,	 float width,        int triangleCount, int nodeID)
{
	if(triangleCount)		
	{
		CPoly *pNodeVertices = new CPoly [triangleCount];
		int index = 0;
		for(int i = 0; i < numberOfVerts; i++)
		{
			if(pList[i])	
			{
				pNodeVertices[index] = pPoly[i];
				index++;
			}
		}
		m_pOctreeNodes[nodeID] = new COctree;
		CVector3 vNodeCenter = GetNewNodeCenter(vCenter, width, nodeID);
		g_CurrentSubdivision++;
		m_pOctreeNodes[nodeID]->CreateNode(pNodeVertices, triangleCount, vNodeCenter, width / 2);
		g_CurrentSubdivision--;
		delete [] pNodeVertices;
	}
}

What does the first if statement actually prove true for? It seems a bit weird to me because I would have thought it only returns true for triangleCount = 1, but he seems to act like it works for values above 1 as well. triangleCount is the intended amount of triangles to put into one node.