Strings: Use alphabetic characters before or between separators (for example, .DEL, @VK@)
Separator: The at sign (@) is used as a separator.
Date: y is the year, m is the month, and d is the date. For example, yy, yyy, mm, dd
The number sign (#): Represents number of digits. For example, ### represents 3 digits.
..###1: Consecutive numbering.
..###2: The number starts at 1 every year.
..###3: The number starts at 1 every month.
..###5: The number starts at 1 every day.
Make sure you do not use the same number twice.
Parent topic: Document Numbers