The apply page  supports 2 new GET parameters cx_applysource and cx_applytags as of version 2.14.36Usage example: 

http://somecustomer.com/vacancy/1234/apply?cx_applysource=Google&cx_applytags=jobboard.nl,paid,regionA

NOTE:
The apply parameters are being stored in a cookie for 30 days. If the same candidate applies for another vacancy through another URL e.g. When a candidate submits the apply form the tracking values will be automatically saved in Match details and become visible in Carerix application as Apply Source and Apply Tags fields in Matches details.

If yours wordpress configured differently and you are not using default urls, be sure that redirect from job board will land on apply page. Usually it is enough to provide apply=true parameter in the url

http://somecustomer.com/vacancy/9876/apply 

The resulting match will be created with previous tracking values. 

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