The mod can show items' Engilish Name as tooltip, like the image below. If your language is en_us, it will do nothing.
Some items don't have localized. When you want to search a item, you may use you native language. However, not all mods are localized to your language. So if the item doesn't localized, you cannot search it in your native language, that is annoyed.
Moreover, it can help translator to see show how a language entry used in the game clearily.
If you want high version(1.15+), See Untranslated Items
