The UK Visas and Immigration authority contains several guides in its website destined for visa sponsors.
There are in particular 12 user manuals about the sponsorship management system (SMS).
Manual 12 (Restricted certificate of sponsorship) contains a section on "How to view previously refused, withdrawn or rejected applications", but for restricted CoS only.
However, there is no mention about whether this exists for unrestricted certificates, in any of the guides.
Is there a specific reason for this asymmetry? Or is the information available, just not mentioned in the guides?
The issue is that, in a given application, can the employer obtain such information without having to ask the migrant? For instance, the migrant may be undergoing appeal/administrative review, but if the employer sees "REFUSED" in their system, they might want to cancel/withdraw the sponsorship/job offer, negatively affecting the migrant.