Nationality, citizenship, and right of abode
UKVI's nationality instructions are at https://www.gov.uk/topic/immigration-operational-guidance/nationality-guidance
Guidance for the Windrush scheme is here: Windrush scheme casework guidance - GOV.UK (www.gov.uk)
Explanation of the Windrush generation nationality issues is here: http://globalcit.eu/the-windrush-generation-and-citizenship/
Details of the Windrush Compensation Scheme guidance are here: Windrush Compensation Scheme casework guidance - GOV.UK (www.gov.uk)
Finally, the Windrush Learned Lessons Review can be found here: Windrush Lessons Learned Review by Wendy Williams - GOV.UK (www.gov.uk)