Will requirements be implemented on a case-by-case basis or will uniform requirements based on fixed percentages be established (for any of the measures)? When measures are implemented through leases, each lease will be negotiated on a case-by-case basis. Every port facility has unique operations, and this approach allows for the greatest flexibility to negotiate strict emission reductions requirements for achieving the goals of the CAAP. Setting fixed percentages for uniform application will not always achieve the greatest emissions reductions. For example, requiring a fixed percentage of calls to cold-iron does not necessarily target the appropriate vessels to achieve the greatest emission reductions and can even work against the goals of the CAAP. Where uniform application of a measure is appropriate, tariffs are being considered.