Final answer:
A justification letter for a local ISG relationship must be signed by a higher-level executive or management official, such as a CIO, the head of Information Security, or a relevant business unit leader.
Step-by-step explanation:
The justification letter requesting a local ISG relationship is typically part of business processes within an organization. The signer of this document is generally a higher-level executive or management official who holds the authority to make such requests.
The exact title of the person required to sign this letter may vary depending on the organization's structure, but it often falls upon individuals such as the Chief Information Officer (CIO), the head of the Information Security department, or the business unit leader directly responsible for the area that will benefit from the local ISG (Information Security Group) relationship.