1. Not required by rule or law
   - nonobligatory

See also: optional

• smallmouthed bass
• smallmouthed black bass
• smallness
• smallpox
• smallpox virus
• smalltooth sawfish
• smalt
• smaltite
• smaragd
• smaragdine
• smarm
• smarmily
• smarminess
• smarmy
• smart
• smart alec
• smart aleck
• smart as a whip
• smart bomb
• smart card
• smart casual
• smart money
• smart set
• smart-arse
• smart-ass