Andre Guirard zur vortlaufenden Nummerierung in Dokumenten (RedWiki)

[m3]

Assigning sequential identifiers is a challenge in Lotus Notes because of Notes' major strengths – its abilities to support high availability through clustering, efficient use of limited bandwidth by creating replicas in scattered locations that are linked by slower connections, and offline access by means of local replicas.  There's no built-in function for sequential number assignment precisely because there are so many common situations in Notes deployments where this could not work.  If a user is working in an offline replica, there's no way, even in theory, to make sure the numbers they assign to new documents are in sequence with numbers being assigned elsewhere.

Lotus Domino Designer wiki: Assigning Unique/Sequential Document Identifiers