The official hanko is the stamp that was registered with the government office that has jurisdiction over the area where he lives. There is also a case to be used to hanko along with a hanko certificate when connecting a separately made an important contract with the day-to-day use private hanko. Official hanko, since the person who press the stamp is also the identification certificate to prove that it is the owner himself, hanko that can be mass-produced as penetration mark can not be registered. Altered resistant material and the copy is not easily typeface is required.
That such a system has been established in Japan, but common people also began to surname haves from the Meiji era. That time there was also movement to try to sign emulating the West, was not established for reasons such as labor office. In countries using the only sign to such contracts, it can not be registered, such as Japan for the handwriting that I can not write in exactly the same in such physical condition. So Have witnessed to a third party, a certificate that he was signed in front of the eyes to convince the person is described, is the tendency is often to get made in place of the official hanko and hanko certificate.