Stamp where there is signature, time and printing name. Do I have to sign it?
Not necessarily. The purpose of stamping is to make it legally effective. Different documents will cover different places. Generally speaking, less formal documents are not very particular. Strictly speaking, only those government documents or court documents will be strictly observed. Normally, our documents will not be strictly observed. Moreover, it is unrealistic for everyone to strictly abide by it, and it will not have no legal effect just because you have built the wrong place.