The overprints were said to have been carried about the middle of 1886 in Sandakan at the offices of the Borneo Herald. This was to facilitate the payment of duties of smaller amounts which was hitherto avoided by merchants, traders and others. Till then only high value adhesives of 25c upwards were eligible for use for revenue purposes.
Yet another borrowed image where the "d" is placed slightly to the right. So this overprint can exist in at least 3 slightly different variations. Possibly this would also applied to the similarly overprinted ten cent value. The account is in this respect is different from the one in Part 1 of The Stamps and Postal History of North Borneo. These latter 2 settings are definitely much more uncommon.