"If thy header files fail to declare the return types of thy library functions, thou shalt declare them thyself with the most meticulous care, lest grievous harm befall thy program.

The prophet Ansi, in her wisdom, hath added that thou shouldst also scourge thy Suppliers, and demand on pain of excommunication that they produce header files that declare their library functions. For truly, only they know the precise form of the incantation appropriate to invoking their magic in the optimal way."

This commendment made me afraid of the dark. Was it common in those days to have to guess to calling convention of libfunctions?