When to give a document several labels

A text should be given two registers when it features characteristics of more than one register.

E.g. when

• a personal blog includes a recipe: Narrative blog + Recipe
• a text describing something also includes instructions: Description of a thing or person + Other how-to
• a marketing text is followed by reviews: Description with intent to sell + Review
• a sport report includes the writer’s viewpoints: Sports report + Other opinion
• a blog post that informs the reader about an upcoming football match and invites them to watch: Narrative blog + Other informational persuasion
• Eulogy with lyrics and decriptions: Lyrics + Other narrative
• See Biber & Egbert 2018: 200

Please note that Encyclopedia articles, like Wikipedia texts, are not by default hybrids.