I encountered a case when a specific font (Nimbus Sans) seems to visually auto-correct string "Nr." (three characters) into "№" (numero sign). "Nr" by itself still looks like "Nr".

I didn't know it is something a font can do, but it seems like it does. Can someone give me a reference to some info on this, please?

I tried both a web browser (Firefox on Linux) and a text editor (LibreOffice Writer), and it happens in both cases.

The characters do not actually get replaced. If I change the font to, say, Arial, or copy paste it into some plain text field, it turns back to "Nr.". But, as long as the font is set to "Nimbus Sans", it looks like a numero sign was typed.

  • 3
    That’s not autocorrect, just a contextual ligature. Most fonts do that (e.g., replace two consecutive f’s with the ff ligature); some do it more extensively than others (e.g., the Font Awesome replacing entire icon names like alarm-exclamation with a single glyph (an alarm clock with an exclamation mark in it). – Janus Bahs Jacquet Dec 21 '20 at 0:06

Most of it is already said in a comment. Many fonts have ligatures - special glyphs which replace certain letter combinations. But programs which use fonts and give to the user some typographic control have somewhere a setting "are ligatures allowed or not". In the next example ligatures are allowed in the selected text:

enter image description here

Not all computer fonts have ligatures. Some fonts have plenty of them. A font which imitate handwriting can need 100 of them or even more.

Ligatures are grouped. Some of them are standard and some are for fun or decoration. In advanced programs one can select which groups are used automatically. Read more here: https://creativepro.com/typetalk-standard-vs-discretionary-ligatures/

The idea of ligatures is much older than computer fonts, they have been common in printing hundreds of years. Ligatures exist also in many manual lettering styles because they help to increase writing speed. That idea was in use a long time before Gutenberg and printed books.

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