According to Wikipedia: A form letter is a document that is sent to many recipients. It is therefore a category of communication logistics. Address, titel and parts of the content are usually personalised and can give the appearance of a personal letter.
Doc2Print: The structure of the form letter must be constantly the same in terms of content (example: all items in the same PDF must have the same number of pages. You define the "number of pages per document" when placing the order. If you want to send documents with different numbers of pages, you create a separate PDF with the corresponding documents for each page number size.
Printer driver: The Printer driver has the ability to recognise the individual start pages of a document based on the address itself. The result of the document splitting is displayed in the programme below.