It means a vendor cannot get the FCC to take action against another vendor for this. Any vendor can make a device using that band (there are many conditions, b

It means a vendor cannot get the FCC to take action against another vendor for this. Any vendor can make a device using that band (there are many conditions, but in principle it is open to anyone). One vendors signal is another vendors noise. Each vendor needs to live with that fact. That could, for example, mean accepting that their device will sometimes simply not work. Compare with licensed bands such as the ones used for LTE. These are (basically) allocated to individual parties for their exclusive use (ie, nobody else can interfere). If a device interferes with those bands, the FCC can take enforcement action (eventually).