Change locale for decimal point and NO thousands separator

I use a Linux system, and would like to have to following default settings in Calc:

Paper format: A4
Decimal separator: “.”
Thousands separator: none

The numbers are the most important aspect. For numbers, this would be the “C” format.

However, I do not manage to set these in LibreOffice (Calc).

I even created my own locale and installed it, but it is not listed as option in LibreOffice (7.3.7).

How can I achieve this?

What is “C” format?
For locale English (New Zealand) the first 3 are already default and if I switch to locale English (UK) or English (Australia) the first 3 are still default.

Ok, these locales work. “C” is the standard posix (or C language) numeric format, one can usually set LC_NUMERIC=C.

What I nevertheless wonder, are these locales hardcoded into LibreOffice, or does LibreOffice somehow read them from the system?

The C locale is the standard POSIX locale, language-country agnostic and originally very limited even in the supported charset, hence usually given as C.UTF-8 instead. It’s basically the locale the C compiler has to support.

For LC_NUMERIC=C locale -k LC_NUMERIC it defines

decimal_point="."
thousands_sep=""
grouping=-1
numeric-decimal-point-wc=46
numeric-thousands-sep-wc=0
numeric-codeset="ANSI_X3.4-1968"

instead of for LC_NUMERIC=en_US.UTF-8 locale -k LC_NUMERIC

decimal_point="."
thousands_sep=","
grouping=3;3
numeric-decimal-point-wc=46
numeric-thousands-sep-wc=44
numeric-codeset="UTF-8"

And no, there is no such C locale in LibreOffice, if LC_CTYPE=C.UTF-8 the locale used in LibreOffice still falls back to en-US.

You mean on the operating system level?

Yes, LibreOffice comes with its own set of locales, and if none matches what was set as LC_CTYPE (sic, yes, for legacy reasons) it falls back to en-US. LC_NUMERIC or LC_TIME or such are not evaluated.

By adding relevant code and locale data definitions and building from source… that’s probably not what you want, so you could file a bug as request for enhancement (RFE) and report back the resulting bug number here in the form tdf#123456.