Just a small reminder that I have not forgotten about North Borneo. These nice markings in turquoise are probably official fiscal markings for documents. I am not entirely sure and perhaps someone can help.
Looks like a company cancel probably as part of stamp duty for some sort of legal or financial document. We have the letters for Albert W B(or E) (?Company) KUD(AT) B N BC. They are quite collectable. Perhaps one can classify them as part of social philately. This is Albert W Nieuveld of Messrs. de Mattos & Nieuveld, shipping agents at Kudat.