Genome Designation vs. Assignation
New Pango lineages are identified and named by the Lineage Designation Committee (LDC), according to the rules set and moderated by the Pango Committee (PC).
Designation
Lineage designation is a **definitive statement of classification**. The designation process involves manual data analysis and curation by the LDC. Sequence designations are made according to the Pango rules. All genome designations are recorded in the sequence designation list.
Assignation
Lineage assignment is an **inference** that in most cases will be accurate but does carry some uncertainty. Sequences can be assigned automatically to lineages using software tools that extrapolate from the sequence designation list to previously-unseen sequences. The most popular tool for assignation is pangolin.
Why are not all sequences designated?
- Some sequences do not meet the quality threshold (e.g., too many missing nucleotides).
- Newly-generated sequences take time to be assessed by the Pango team.
- Some Pango lineages are so large and contain so many identical genomes that it is not practical to designate every possible member.