Options > Settings > Company > Management > Change tracking (numbering of the revision index). In the dialog Settings: Change tracking (numbering of the revision index), in the Available format elements list, select a format element of type 'Counter' and click (Move to the right) (or double-click an already defined counter in the Selected format elements list).
In this dialog you specify the formatting for a counter in the format group.
Overview of the main dialog elements:
Here you define the minimum number of characters to be used for the property value. Longer values are displayed in their full length. Only positive numeric values are permitted. A value of zero means that the field width is variable.
You can define a padding character here. The value is padded with this character if the minimum field width is larger than the width of the value. A padding character cannot be entered for a variable number of digits (entry of "0" in the Minimum number of digits field).
If this check box is selected the alphanumeric counter is used. If not, a numerical counter is used.
When using the alphanumeric counter specify the characters here that are allowed to be used by the counter. Only alphanumeric characters are allowed.
Alphanumeric counters are sorted by character from left to right (in the same manner as Excel columns). If you have specified, for example, the characters "AKS", counting proceeds as follows: A, K, S, AA, AK, AS, KA, ..., AAA, AAK, AAS, AKA ..., AAAA, AAAK, ...
See also
Dialog Settings: Change tracking (numbering of the revision index)