Commissioned recipe and the 'Banzhang' claim
8582 (1985, grade 8, Menghai) is said to have been created for a Hong Kong trading company, rendered 'Nan Tian' or 'Lan Tian' depending on the source, before becoming a standard Menghai product. Some 1990s batches are sold as 'Banzhang 8582', but sources making that claim do not document leaf origin.