How do I insert a thin space in Libre in Windows?

[anne-ology]

it may or may not be in the character-map for the particular font
you're using

       Now, ... Printing started back in Roman days ... then the Printing
press began with Gutenberg ...
          then ... then ... then ...
        Latin was the language of the Romans, thus these abbreviations stem
from that

       BTW - for you young folks, Latin & Greek were taught to all students
... then a Romantic & a Germanic language (well, in the British & American
schools)

       nota when spelled out looks as if it starts with our modern-day u