Spanish to English Bus/Financial Business/Commerce (general)

The rest of the sentence is as follows:

DOCUMENTO DE COBERTURA DE RIESGOS PROFESIONALES CON MUTUA O PATRONAL O CON EL ISSN

There are a few bits I'm struggling with, the "con mutua o patronal" and also the "ISSN".
I don't know how the ISSN fits in this context so am wondering if it's a type and they mean INSS as they do refer to seguridad social in different places in the document but I could be completely wrong.

The document itself describes the documents that contractors/subcontractors need to supply.

Any advice would be much appreciated, thanks.