Proof of resignation.
The resignation certificate is the most important thing, and under normal circumstances, it is necessary for us to provide when we join the next company, and the resignation certificate can show that we have no relationship with the previous company.
Employment contracts. Needless to say, I believe I will take it home when I get the offer.
Certificate-related. 
Certificates, patents, etc., if not agreed in advance, are to be taken away, which is a manifestation of their own ability, and some certificates are attached to additional income, I believe we already know when we research.
Proof of termination of employment contract.
If you plan not to look for a job for a period of time, or are worried that you will not be able to find a good job for the time being, you can ask if you can provide it, and this certificate can help us apply for unemployment insurance. However, in many places, the application for unemployment insurance is very simple and convenient, and it is not necessary to look at local policies.
Proof of salary. 
In fact, this is the most useless, although many companies will now require proof of previous salary, but it is generally required to obtain bank statements, not paper certificates, and most companies will not issue such certificates. However, if you can open it, you can also ask for a copy.
So, in fact, the most important of these is the resignation certificate, of course, if there is no upper limit to the ability, these are floating clouds.
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