5.

The Engineer will express an opinion of an engineering subject only when founded on adequate knowledge and honest conviction.

[See Codes C5., II.3.b. ]

Code is relevant when:

Engineer experesses an opinion on an engineering subject

Code is violated when:

Engineer's opinion is not based on adequate knowledge
OR
Engineer's opinion is not based on honest conviction

Code is not violated when:

Engineer's opinion is based on adequate knowledge
AND
Engineer's opinion is based on honest conviction