[Tagging] Feature proposal - RFC - Documenting feet as an an optional elevation unit

[Warin]

On 29/1/24 06:30, Philip Barnes wrote:
> The legal definition of a foot is of course  0.348 m.
>
> "Since an international agreement in 1959, the foot is defined as 
> equal to exactly 0.3048 metres'.
>
> Phil (trigpoint)


NPL has a nice history on length measurement

http://resource.npl.co.uk/docs/educate_explore/posters/bg_historyoflength_poster.pdf


Even in the USA the survey foot is depreciated.

https://amerisurv.com/2023/02/09/the-deprecation-of-the-us-survey-foot/

Depreciation in the US may be 'complete', at least in government 
circles, in 2025...



>
>
> On 28 January 2024 18:57:45 GMT, Minh Nguyen 
> <minh at nguyen.cincinnati.oh.us> wrote:
>
>     Vào lúc 04:08 2024-01-28, Greg Troxel đã viết:
>
>         Minh Nguyen <minh at nguyen.cincinnati.oh.us> writes:
>
>             Vào lúc 19:50 2024-01-27, Brian M. Sperlongano đã viết:
>
>                 Uh so I did the math, and unless I've got this wrong,
>                 the difference between survey feet and international
>                 feet for tagging, let's say, Mount Everest, is less
>                 than seven one-hundredths of an inch.  So I'm really
>                 not even sure why we're discussing it beyond the fact
>                 that we're all nerds about this sort of thing. 
>
>             You got me. :-) The actual proposal doesn't mention the
>             foot's two definitions at all, and so far I'm planning to
>             keep it that way. 
>
>         I think it's important to be definitionally correct, even if
>         it doesn't really matter. It's a slippery slope, and pretty
>         soon \pi is 3. 
>
>     Poor Indiana. ;-) The definition of the foot would apply to the '
>     and ft abbreviations in every context, not just the ele=* key, so
>     I'd suggest considering it separately, probably without the
>     formality of a vote. The main unit symbol listing has come
>     together more informally over the years. [1] Sooner or later,
>     OpenHistoricalMap will have a lot of fun with this issue... [1]
>     https://wiki.openstreetmap.org/wiki/Map_features/Units
>
>
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