New Zealand Information Security Manual (NZISM) 15.1.10.C.03: 15.1.10.C.03 Prevent downgrading markings on replies and forwards

Agencies should not allow a system user who is replying to, or forwarding, an email to pick a protective marking showing a lower classification than one previously applied to that email.

Maintained by Gerard BlokdykVerified against the published standard 31 May 2026Control text last updated 21 May 2026

Other controls in Chapter 15: Email security – New Zealand Information Security Manual (NZISM)

15.1.10.C.01 15.1.10.C.01 Restrict selectable markings to the system's accreditation level
15.1.10.C.02 15.1.10.C.02 No automatic marking insertion without user action
15.1.11.C.01 15.1.11.C.01 Every email carries a protective marking
15.1.11.C.02 15.1.11.C.02 Email marking reflects the highest classified element
15.1.11.C.03 15.1.11.C.03 Place marking in subject line or header
15.1.12.C.01 15.1.12.C.01 Assess unmarked email received from outside government
15.1.13.C.01 15.1.13.C.01 Do not mark purely personal emails
15.1.14.C.01 15.1.14.C.01 Contact originator of unmarked government email

Query this from an agent

The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.

MCP endpoint All New Zealand Information Security Manual (NZISM) controls