The purpose of this session is to improve the standardised reporting of variants using a pangenome reference resource, with emphasis on larger, structural rearrangements and haplotype identification. In doing so, we will facilitate engagement across several different GA4GH working groups, such as the Genomic Knowledge Standards (GKS) Work Stream, the Large Scale Genomics (LSG) Work Stream, the VCF product team, and the Human Pangenome Project (HPP) Driver Project. In particular, this session is useful to identify gaps for representation of large structural variants using the GA4GH VRS v2.0 structural variation models. This session will focus on a current US-based initiative of the HPP, that anticipates a beta public release (470 haplotypes) in Spring 2025 that would benefit from having standardised reporting of complex variation. This will offer an important first technical meeting with the Pangenome technical team and GA4GH Work Streams to allow cross-collaboration. This working group session will be highly interactive, offering short, select presentations and open-floor discussions. This meeting aims to identify a path to an HPP-GA4GH improved standard for variant calling.