1. Entirely at the artist's discretion without obligation or regulation.
2. Intended to be allowed by the viewer by "willing suspension of disbelief, discrimination and orthodoxy".
3. Considered to be useful to fill in historical, educational, compositional, representational "gaps".
4. Can be used consciously, unconsciously, intentionally, unintentionally or in tandem.
5. Also commonly known as "Poetic License": justifiable departure form convention, rules of form, fact etc.
6. Generally earned with skill, merit, fame or degree.