The Bureau of Industry and Security (BIS) maintains, as part of its Export Administration Regulations (EAR), the Commerce Control List (CCL), which identifies certain items subject to Department of Commerce jurisdiction.  Pursuant to the Export Control Reform Act of 2018, BIS and its interagency partners are engaged in a process to identify emerging and foundational technologies that are essential to the national security of the United States.  Emerging technologies essential to the national security are those that may warrant stricter controls if present or potential application or capability of that technology poses a national security threat to the United States.  This rule proposes to revise the CCL to control extreme ultraviolet (EUV) masks, reticles, and pellicles as emerging technology.