VL was employed by a hospital in Kraków (Poland) from October 2011 to September 2016. In December 2011, she obtained a disability certificate, which she submitted to her employer that same month. In order to reduce the amount of the contributions payable by the hospital to the Państwowy Fundusz Rehabilitacji Osób Niepełnosprawnych (State Fund for the Rehabilitation of Persons with Disabilities) (PFRON), the director of that establishment decided, following a meeting with the staff which took place in the second half of 2013, to grant a monthly allowance to employees who, following that meeting, submitted certificates attesting to their disabilities. On the basis of that decision, the allowance was granted to thirteen workers who had submitted their certificates after that meeting, whereas sixteen other workers, including VL, who had submitted their certificates earlier, did not receive that allowance...