Removed two incomplete examples. They can be re-added if someone knows the title of the work in question, but otherwise it's not useful to have an example that doesn't say what work the example's from.
A Phyllis Eisenstein character was trying to find out who his father was. His father (currently in the form of a young girl and by now a friend) was forbidden to tell anyone, but by silence and elliptical statements managed to make the whole story clear.
In a short story by Selma Lagerlöf, a young girl kidnapped by bandits has to solemnly swear she'll never tell what happened and where they're hiding to anyone. After escaping, she tells how to find them to her cat, while the family's in the room.
Removed two incomplete examples. They can be re-added if someone knows the title of the work in question, but otherwise it's not useful to have an example that doesn't say what work the example's from.