Asterisk is an icon, not label text
asterisk-is-icon-not-label-text
Required marker uses a spaced icon. If you use an asterisk, include hint text that explains what it means. Never use an asterisk to mark optional.
Description
Required marker uses a spaced icon. If you use an asterisk, include hint text that explains what it means. Never use an asterisk to mark optional. Pass when required is a spaced icon (not asterisk characters inside the label string), hint text explains the marker, and optional is not marked with an asterisk. Fail when asterisk is typed as label text, there is no explanation of the marker, or asterisk marks optional.
When to use
Marking required fields on Spectrum text fields and forms.
Not when
Asterisk typed into label text, unexplained markers, or asterisk-marked optional.
Agent hint
Mark required with a spaced icon plus hint text; never use asterisk for optional.
Required is a spaced icon (not asterisk characters inside the label string); hint text explains the marker; optional is not marked with an asterisk.
Asterisk is typed as label text; no explanation of the marker; or asterisk marks optional.
Citations
Spectrum — Text field
https://spectrum.adobe.com/page/text-field/