United Kingdom - Passport & Nationality - British Citizenship by Descent (Mother Registration)
This solution to British citizenship arises where an applicant's mother was registered as a Citizen of the UK and Colonies (or CUKC - the former term for British citizenship). Depending on the manner in which this registration occured, she may have gained the right to pass this British nationality down to her children. Recent changes to remedy gender discrimination in the older nationality law now allows claims to come down the maternal side of the family.
This also may allow the children of the successful applicant - i.e. the grandchildren of the woman registered before 1983 - to be registered as British citizens if the parent has spent at least 3 years in the UK. This is because their maternal grandmother is considered as being British otherwise than by descent.