Conspiracy can be put to rest... New details on the Citigroup bug that resulted in the omission of blue-sheet data for 15 years: The glitch resided in new alphanumeric branch codes that the bank had introduced in the mid-1990s. The program code filtered out any transactions that were given three-digit branch codes from 089 to 100 and used those prefixes for testing purposes. The report adds, "But in 1998, the company started using alphanumeric branch codes as it expanded its business. Among them were the codes 10B, 10C and so on, which the system treated as being within the excluded range, and so their transactions were removed from any reports sent to the SEC." https://it.slashdot.org/story/16/07/13/2037222/programming-bug-costs-citigroup-7m-after-legit-transactions-mistaken-for-test-data-for-15-years