This ballot includes proposed modifications to the Appendix (Nonmandatory Information), Section X1.4 Combustion of ASTM D1655. -Some wording updates are being proposed to align the context with the entirety of the fleet-wide combustion technology. Past wording was appropriate only for rich-burn combustion technology that had been prevalent, however, over the last decade lean-burn combustion technologies have penetrated the field and are now utilized among the fleet. -Over the last decade various studies, such as the National Jet Fuel Combustion Program and OEM internal studies, have demonstrated an apparent correlation between Cetane Number and various combustion related concerns such as combustion lean-blow-out and auto-ignition induced combustor hardware distress (some background material presented below). Although the physics and science behind the relationship are not yet fully understood, the correlation has been well established. Therefore, an informative sub-section X126.96.36.199 on Cetane Number is being proposed for addition to the Section for the benefit of the users of the standard, similar to the smoke and aromatics information already present in the same Section. The motion to ballot was approved by the Subcommittee J Chairman in an email dated April 27, 2021.