Character tags make NovelAI draw a specific licensed character: hairstyle, hair and eye color, default outfit and props in one word. Add the copyright tag to pull in the series look as well. 21,192 tags are listed for V4.5.
About 20,000 character tags verified through NovelAI's suggest API and nax.moe. Same prompt and seed throughout, only the character tag swapped, so you can see which characters reproduce fully and which only get the hairstyle.
Put the character tag first, then the count ("1girl, solo"). Adding the copyright tag avoids name clashes and stabilizes the outfit. Use Danbooru's English spelling, parentheses included (rem (re:zero)).
Top-scoring character tags.
V5 recognizes recent characters better; V4.5 covers more vintage anime and doujin material. If V5 breaks, try V4.5.
How do I change the outfit?
Add "alternate costume" and then the outfit tag after the character tag.
Are the images from the original works?
No. They are NovelAI samples generated from the tag.