Legally Required?

Your answer would lie in your nurse practice act (since I don't think you're in the US).

In the US, the full diagnosis/related factors/evidence/intervention format for developing nursing plans of care is what educational programs require to teach students how to think about how nursing diagnosis is a result of evidence gleaned from assessment and causation-- a strong tool in teaching the nursing process. When students graduate, state nurse practice acts (we don't have a national one, alas, but the ANA Scope and Standards of Nursing Practice does apply to all of us) require evidence of nursing process resulting in a plan of care developed and implemented/delegated by a registered nurse, but doesn't require the full format used in school. An individual facility may have other standards.

I don't think the verbiage police will come and arrest you if you deviate, but utilizing standardized methods in care planning that incorporate the nursing process throughout provides evidence that the standard of care was met in case that should ever come into question...in my opinion.

We've successfully passed many state and Medicare audits without using that verbiage.

I dothink it's a good learning tool for nursing students to develop plans of care appropriate to the patient and their scope of practice.