Dear RIPE IPv6 WG, As promised at last RIPE meeting in Madrid, we produced a first draft of "Best Current Operational Practice for operators: IPv6 prefix assignment for end-users - static (stable) or dynamic (non-stable) and what size to choose." The aim of this document is to document the best current operational practice on what size of IPv6 prefix ISPs should assign/delegate to their customers and should they delegate it in a stable, static way or should it change over time. Please find the PDF attached and also accessible at: https://www.sinog.si/docs/draft-IPv6pd-BCOP-v1.pdf We are submitting this document to RIPE IPv6 WG (here) to check the technical validity of the document and also get consensus on it. We are also submitting it to RIPE BCOP TF to check if this is a real best operational practice and get consensus on it there. Please, read the document and send back comments to this mailing list. All feedback is more than welcome. On behalf of co-authors, Jan Žorž P.S: This document is not intended to document what practices may be in future and what they might look like, but to reflect the best methods of implementing IPv6 at the time of publication. Updates to this document will be published to reflect changes in best current practices where there are developments in standards and implementations.