Command Papers derive their name from the fact that a Government minister presents them to Parliament "by Command of Her Majesty". The titles which form this series of publications are often described as "White" or "Green" Papers but these expressions have no formal definition; it has become accepted that White Papers are statements of Government policy whereas Green Papers are proposals which are published as an aid to public debate.
House of Commons Papers (HCPs) are a large and varied body of documents, numbered consecutively in a series which starts with each new Parliamentary session. This series includes those HCPs which originate in Government departments, the reports emerging from investigations undertaken by the head of the National Audit Office (the Comptroller and Auditor General) and the Parliamentary and Health Service Ombudsman. Reports from major inquiries are also published in this series,as well as publications associated with Select Committees in the House of Commons.