Deprecation of the U.S. survey foot

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This is an editorial comment regarding the section on the U.S. units of survey length equal to 1200/3937 m. NIST issued an opinion in the Federal Register (U.S. legal regulations) of a final decision to deprecate the survey foot from use in any new or derived works, at least official U.S. works. The international foot is now the official foot to be used in the U.S. This means that there is an opportunity to add "default" foot, mile, etc. to the international customary units, e.g., [ft], [mi]. It may be worth noting this information in the text regarding the U.S. survey units, or simply adding the reference and notice from it.

The following notice is taken from NIST HB-44, 2024 ed., Apdx. C, pp. C-10 and 11 (see footnotes).

NOTICE: In collaboration, National Oceanic and Atmospheric Administration (NOAA) and NIST have taken action to provide national uniformity in the measurement of length. The final decision to retire the U.S. survey foot was published in the Federal Register, announcing the deprecation date of December 31, 2022. Beginning on January 1, 2023, the U.S. survey foot should be avoided, except for historic and legacy applications and will be superseded by the international foot definition (i.e., 1 foot = 0.3048 meter exactly) in all applications. Prior to this date, except for the mile and square mile, the cable’s length, chain, fathom, furlong, league, link, rod, pole, perch, acre, and acre-foot were previously only defined in terms of the U.S. survey foot. With this update, relationships are available in terms of the international foot, which can simply be referred as the “foot.” Either the term “foot” or “international foot” may be used, as required for clarity in technical applications. This is particularly the case for surveying and mapping applications, although over time “foot” will become more prevalent. The preferred measurement unit of length in the United States is the meter (m) and surveyors, map makers, and engineers are encouraged to adopt the SI for their work. For more information see Federal Register (October 5, 2020, 85 FR 62698, p. 62698) available at https://www.govinfo.gov/content/pkg/FR-2020-10-05/pdf/2020-21902.pdf.

NIST Handbook 44, 2024 ed. Konijnenburg J, Lee GD, Minnich LB, Williams JS, Warfield L, and Lippa K (2024). Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices as adopted by the 108th National Conference on Weights and Measures. (Washington, DC: National Institute of Standards and Technology). https://doi.org/10.6028/NIST.HB.44-2024