If the detail is not new, the counters are not touched. The substantial difference is between the counters of the local and the cloud databases: for the cloud databases the counters are managed directly by the server and upon saving the program will ask the server for the number to be assigned to the counter. This is due to the fact that multiple devices may request a number to be assigned at the same time and therefore the information must be centralized. If it is not possible to receive the number at the time of saving, the server will automatically assign it during data synchronization.
The counters allow you to manage an entry mask. If you want to write something beyond the progressive number you will have to write it in the mask column: to add the year 2017 preceded by / you will have to write / 2017 in the mask; to add letters or fixed numbers before the progressive number, it will be necessary to write them followed by a * (ex: PR1 = PR *); to add zeros before the number it will be necessary to write as many asterisks as there are zeros that must precede the number (ex: 0001 = *** 1).