The Self Assessment Questionnaire is defined by the Payment Card Industry Data Security Standard (PCI DSS).
Six Sigma refers to a process-focused methodology designed to improve business performance through improving specific areas of a strategic business processes.
A Specification (Shortcut: Spec.) is a technical standard. It consists of a set of requirements to be fulfilled by the product or service.
If at least one requirement is not met, the product is "out of spec."
While the above describes how a product/service should be, the term 'specification' is also used to describe, how a product7service really is. This would be more the meaning of a data-sheet.