Recoded "bp31" to make invalid units missing, fixes #86
Recoded "bp22" to make invalid units missing, fixes #85
Recoded "bp21" to make invalid units missing, fixes #84
Recoded "bri9c" to make invalid units missing, fixes #83
Recoded "bri9b" to make invalid units missing, fixes #82
Recoded "bri9a" to make invalid units missing, fixes #81
Recoded "bri3c" to make invalid units missing, fixes #80