(Calc) How to turn off auto-correct absolutely, wholly, and permanently

I work with phylogenetic trees and language ISO codes. It is of the highest importance that I type in these codes correctly. For instance, the code for the Ngwe language of Cameroon is nwe. If LibreOffice swaps nwe for new per the autocorrect feature, I could lose days in debugging.

I need a 100% fool-proof method for making sure that this will never ever happen. This ain’t like a typo in a CV, the system works on these codes being right.

Thanks for the help

NPerrault, I am involved in similar language work in NE Africa. Our solution is to NOT disable spell checking, but rather to change the default Language setting to NONE. This way, if we create any document (vernacular or national language), it will NOT have spell-checking on by default, and thus no auto-correcting either. If the document is English (or another “majority language”), then we hilight ALL, and click at the bottom center to choose the language. Then spell checking is applied and “red squiggles appear”. The advantage then, is that spell-checking is not disabled for ALL languages, but is disabled by default on new documents UNTIL the language of the document is set to a language supporting spell-checking.

You can do this in Tools | Options | Language Settings | Languages | Default languages for documents: Western. Choose [None].

UPDATE: I just noticed you are specifically inquiring about this in Calc. In my preference I would still handle it in this way, to NOT have a default language set. But your use case may prefer to not deal with this and just disable auto correct as the other answer suggests.
Additionally, we adjust the following auto-correct options:

- Disable Capitalize first letter of every sentence

- Disable “TWo INitial CApitals”

- Disable “Replace Dashes”

- Disable automatic bold and underline

Thank you, this was very helpful.

Disable the options in:
Menu/Tools/Autocorrect Options/Options.
and verify if it works fine for you.

If it is something he needs to verify, then it is not a foolproof method, just yet. That is basically the same as giving no answer at all because there might be a potential conflict for a new document, or whatever.

that worked for me, thanks. I couldn’t see the “options” button in autocorrect options