The most common reasons for using entities rather than Unicode characters are:
- If your keyboard does not support the character you need to type, eg many keyboards do not have em-dash or the copyright symbol.
- If your editor does not support unicode (not an issue for Sigil, of course!).
- When you want to make it explicit in the source what is happening, eg the code is clearer than the corresponding whitespace character.
- When you need to escape HTML special characters like >, &, or ".