To the point

Hahn Air now supports Interline Electronic Miscellaneous Documents
(IEMDs). The new service is available on Amadeus, with other GDSs
to follow soon. The EMD is an Iata standard document sold via the
GDS to enable the indirect sale, fulfilment and tracking of usage of
ancillary airline services in one seamless process. However, airlines
can only sell their EMDs in markets where they have joined the
local settlement system (BSP). With an interline agreement, partner
carriers can now sell their services via Hahn Air’s HR-169 IEMD.