United Kingdom - Passport & Nationality - British Citizenship by Double Descent (UK-born grandparent)
This solution affects those people born between 01.01.1949 and 31.12.1982, with a parent born between 01.01.1949 and 31.12.1982, and who have a UK-born grandparent. It relies on an anomaly in the the definition of "by descent".
This interpretation must also take into account gender discrimination. As the law is currently drafted, a claim could not come through a grandmother, only a grandfather, because old nationality legislation only allowed claims to come down the male side of the family. However, it is possible that the law will change to rectify this. At this point in time, the Home Office have ruled that such a claim does not exist.