Here is an extract from MSLT.
It is quite common these days for people to have a desktop as well as a notebook at home. So, it will be unfair to buy multiple licenses of MS office in order to use it on both the PCs. That must be the reason behind this not so well publicized licensing. The same logic holds good for other productivity suites as well. So make sure you do the painful reading of the license terms before buying an additional license.
