I have seen the term ‘General Register of the Poor’ used. Does this refer to a central register of the poor, kept nationally for the whole of Scotland?

No, the term ‘general register of the poor’ refers to a type of poor relief register kept by individual parishes. In 1865 the Board of Supervision introduced new General Registers of Poor and Children’s Separate Registers. Where poor relief registers survive they generally are found among county council and civil parish records in local authority archives and libraries.