Infrared absorbing compounds in which the anion is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate are disclosed. Programming of such memory devices includes programming to a target threshold voltage range representative of the desired bit pattern. Sufficiently long passages found in the copied document that match previously indexed documents held by the service constitute copyrighted materials. This immediately returned spread spectrum transmission allows a reduced complexity spread spectrum receiver within the tag to despread the return signal without having to determine the timing of the clock signal used to produce it. When the cause that all the pieces of performance data could not be acquired is the execution of zero suppression at nodes N1 to Nn, the data items related to the pieces of performance data that could not be acquired are made zero and the resulting data is outputted.