I have no idea what 2.4.6 and 2.5.5 are ?
I presume the context is haccp. I really, really hope you have a haccp plan.
(1) non-conformance = (1) non-compliance (nouns)
(1 item) non-compliant = (1 item) non-conformant (if it exists) (adjectives)
Corrective Action - (haccp Critical Limit Failure))
(See the haccp plan/critical limits) > If yr HACCP plan says a deviation outside the CL requires a corrective action, then the deviation/corrective action is specified/documented in a NUOCA* Form. If it doesn't say a corrective action is required, then complain to the HACCP Plan designer.
Corrective Action (Any other Significant Deviation related to the HACCP plan)
Use a Corrective Action Form and specify/document the deviation/corrective action similarly, eg failure of HACCP Prerequisite No.XYZ
*NUOCA = Notice of Unusual Occurrence and Corrective Action
Plus there should be a section for a Root Cause explanation on the form(s) if required.
Other people will have different preferences. There's no absolute method AFAIK
Rgds / Charles.C
PS - I suspect a NCR is a Non-conformance Report
PPS - just noticed a little SQF tag at the top. Maybe try the Glosssary.