I have an archival pen and write on a piece of fabric. Fold into a triangle. Place onto back corner with binding and the just blind stitch the hem.
If you piece your back - include a piece of white - then just include label there.
If the quilt is for a special person - I write Name, date , occasion. Then my name & town. Finally I add washing instructions: "Machine wash cold, tumble dry low"
You can leave out the names but i believe the historians want the remaining.