Methods and systems for coding SAW OFC devices to mitigate code collisions in a wireless multi-tag system. A plurality of sequences of bits is provided using a convolutional encoder, in response to a sequence of input bits, each sequence of bits being defined by a predetermined generator polynomial having a predetermined level of sensitivity to puncturing. The polymorphic note manager then generates the polymorphic note in response to the request and stores the polymorphic note for access by the device.