Help understaning about work certificates

[George Lind]

Attached is an image taken from the household examination records of the parish of Valla on the island of Tjörn 1862-1872.
The phrase is "Bevis för utrikes sjöfart  25 Jun 1867" which I believe translates to "certificate for foreign shipping" along with the date issued.   This phrase is found next to the names of a lot of men in the parish books including some of my relatives. I believe that you would need this to get a job as a sailor on a foreign ship.  Why would someone need a certificate for this purpose?  In order to get one did you need to have certain skills or pass a test?  Who would have issued this certificate?  Is there a record of these certificates still around today?  I have been unable to find any mention of these certificates anywhere.  Were they only around for a short time?

Here is the link to the original document on the Swedish National Archives.
https://sok.riksarkivet.se/bildvisning/C0042648_00011

Thanks,
George
 

[Ulf Berggren]

It's probably a kind of working permit.

[George Lind]

Ulf,
Thanks for your help.
George