Redundant tag; most posts on Danbooru are focused on female characters. Try {{-1boy -multiple_boys}} or some variant thereof instead:
- {{1girl}} (one female, with or without males)
- {{1girl solo}} (one female, without males)
- {{1girl solo_focus}} (one female, with offscreen males)
- {{multiple_girls}} (multiple females, with or without males)
- {{~1girl ~multiple_girls}} (one or more females, with or without males)
- {{~1girl ~multiple_girls -1boy -multiple_boys}} (one or more females, without males)
If you are looking for the Females Only tag as it is used on E-Hentai and other sites, the Danbooru equivalent is simply Yuri.