Obiter dictum
something said by the way
Where the phrase comes from
A remark in a judgment that was not necessary to the result. The plural is obiter dicta. It can persuade. It does not bind.
What lawyers are pointing at
High-court dicta are read with care, and later cases sometimes adopt them. Until that happens they are not the law of the earlier case. Quoting a side remark as if it were the holding overclaims the report. The disciplined habit is to label the sentence: holding, or aside. Readers who skip the label pass off a comment as a rule.
The same shape in code
A TODO, a commented-out alternative, and a sentence in a postmortem that was not the cause are obiter. They are worth keeping where they are. They are not the interface, and they are not the runbook step. Shipping the aside as the contract is how callers depend on a remark you never meant to keep.
A concrete picture
The court holds that this statute does not apply to ships. In the last paragraph a judge wonders aloud how the statute might apply to aircraft. The aircraft sentence is obiter.