This invention provides novel reagents for cyanating polysaccharides in aqueous or part aqueous solutions so that they may be covalently linked to proteins either directly or through a spacer. The platform has a recess in an upper surface sized and shaped to provide a gripping surface for a ladder rung. Common case local quiescent state tracking may be performed using only local per-reader state information for all readers that have not blocked while in a read-side critical section in which the data element is referenced. When an altered token is detected, the copy may be considered to be an unauthorized copy and handled accordingly. Volumetric scanning is possible by periodically modulating the magnitude or frequency of the signals applied to the coils.