Keeping Knowledge, and Keeping it Connected: Digital Preservation, PIDs and Metadata

While the share of digital only objects in library holdings and scientific output is growing rapidly, the comparative short life span of both digital resources and the tools needed to access them make them vulnerable to damage and loss. Geopolitical developments have been adding to this vulnerability, putting political and financial pressure on institutions providing important public data bases. Digital preservation counters these inherent and external tendencies to dissolution by securely archiving resources, keeping their contents both intact and readable. Yet to retrieve resources from possibly dark archives when they are lost from public data bases we need findable metadata telling us where to look. This talk gives some suggestions about which kind of PID metadata could be useful for documenting digital preservation and aid recovery, and what else might be needed. These slides were presented at PIDfest 2026, held in Leiden, the Netherlands, from October 27 to 29, 2026.