Esto sucede cuando una computadora lee un texto escrito en un formato (como UTF-8) pero intenta mostrarlo en otro (como Windows-1252 o ISO-8859-1).

| Problem | Example | |---------|---------| | | A zero-width space makes two identical words look different to a database | | Input validation errors | A username with a right-to-left mark breaks login forms | | Encoding corruption | “Café” becomes “Café” when saved as ASCII | | Visual confusion | Cyrillic ‘а’ looks like Latin ‘a’ but isn’t—used in homograph attacks |

Esenciales en ciencia e ingeniería, como ∑ (sumatorio), ∞ (infinito) o ∂ (derivada parcial).

Rare characters are special characters that are not commonly used in everyday writing. They can include: