The application contains company details (name, registered address, actual address, etc) and information on the foreign employees it plans to hire - job title, county of origin, number, etc. So far practice shows these points are essential and cannot be changed (i.e. you cannot hire an employee for the position not reserved in the application). Other points of the application (whether the company will rent a flat for the foreign employee, give him additional medical coverage; years of job experience of the employee, education, etc) are merely formal and are not taken into account when the company applies for the work permit.