A method, apparatus and product for use in generating a remainder based code generates a plurality of preliminary remainder based codes in response to specified data, and synthesizing a remainder based code for the specified data, in response to the plurality of preliminary remainder based codes. The method begins by obtaining an indication of whether a non line of sight signal condition is present or likely andor obtaining an indication of whether a multi-path signal condition is present or likely. A flux of metal ions is generated across the film-stamp interface, and a pattern of recessed features complementary to the pattern of relief features is created in the conductive film. An optical emitter receives the output signal and generates an optical signal as a function of the output signal. The valve member is rotatable in the housing and comprises a sleeve and a spool, wherein the spool is rotatable within the sleeve.