CIA Code 39 Medium Text font is a humanist sans-serif font designed specifically for use in Department of Defense (DoD) and National Security Agency (NSA) materials. It was originally created in the 1970s by the Central Intelligence Agency (CIA) for internal use and was later declassified and released to the public. This font is highly legible and suitable for a wide range of uses, including printed and digital documents, signage, and labeling. It has become a popular choice for anyone looking for a highly-readable font with a neutral aesthetic.