A bingo card in online feminist discussion is a square (usually 5x5, with the centre square being free space) of catchphrases or ideas signalling typical anti-feminist (or racist, ableist, etc) arguments. Generally speaking, meeting one square on a bingo card is not necessarily a sign of a problem, but meeting several either in one comment or when explaining your position over several comments, is considered a sign of either a concern troll or allies who need more feminism 101 background reading or a privilege check. In theory one would play bingo with them, ie, wait for someone's arguments to match an entire row or column, in practice they act as more of a checklist.
The cards may be derived from the idea of buzzword bingo in geek circles, in which bingo cards are made containing corporate-speak ("synergise", "human resources", "redeploy") and geeks in a meeting wait to see who is first to get bingo on a row or column.
Anti-feminist bingo Edit
Lauredhel has assembled two anti-feminist bingo cards:
Examples of other bingo cards Edit
Geek feminist/online culture bingosEdit
This is not comprehensive.