to Fig. 2c, the initial peak at $\Phi=0$ spreads out within the first 100 MCS and the maximum at $\Phi \simeq 2$ starts to grow by 200 MCS to reach a considerable height already at $2 \cdot 10^3$  MCS. The $\Phi\simeq 2$ peak is very narrow, indicating a nearly perfect local order in the system. Additional small, sharp peaks at multiples of $\Phi=0.5$ may be traced back to the domain walls that cross some of the blocs of $4\times 4\times 4$ fcc–cells used to prepare Fig. 3c. Slow coarsening processes, which in this case set in already for $t > 2 \cdot 10^3$ MCS result in considerable sharpening of the main $\Phi \simeq 2$ peak.

To better illustrate the differences between the two ordering scenarios described above we show in Fig. 4 how $V_{ord}$, the volume fraction of the ordered phase, grows with time for a number of final temperatures. There, we counted as ordered all the blocs (of $4\times 4\times 4$ fcc–cells each) for which $\Phi >1.5$. The character of $V_{ord}(t)$ changes from a slowly increasing function of $t$ for $T_f \le 0.911\,T_0$ to a sharp, nearly stepwise growth after some incubation time for $T_f>0.972\,T_0$.

In the next two 