Insert special characters - digraphs

 :help digraph

Digraphs work by pressing CTRL-K and a two-letter combination while in insert mode.

While in insert mode, you can insert special characters in Vim by pressing followed by a two-character lookup code. For example, ?2 will insert the approximately equal symbol: ≈

https://vimdoc.sourceforge.net/htmldoc/digraph.html#digraph.txt https://vimdoc.sourceforge.net/htmldoc/digraph.html#digraph-table