Level 1 allows string expansion (<a href="http://tools.ietf.org/html/rfc6570#section-3.2.2">Section 3.2.2</a>)
Level 3 allows string expansion with multiple variables (<a href="http://tools.ietf.org/html/rfc6570#section-3.2.2">Section 3.2.2</a>)
- Companion
- object