There are valid legal and moral issues here, but there were also real-world questions without good answers.
Military discounts are not valid on all sailings and may be limited to a certain number of cabins.
The license must be valid and remain valid for the entire time they wish to rent the vehicle.
Most hotels require a valid credit card number to hold a reservation.
When so taken up, it is not to be abandoned without reason as valid, as fully and as extensively considered.
It is no valid objection that science as yet throws no light on the far higher problem of the essence or origin of life.
However, the reference is valid and useful in the context of the article.
The findings, they say, raise serious questions about the use of student evaluations as a valid measure of teaching quality.
If you're still in contract negotiations, you still need one of those valid excuses.
If you felt they were rude on the phone, that's certainly a valid reason for not wanting to work for them.
British Dictionary definitions for valid
having some foundation; based on truth
legally acceptable a valid licence
having legal force; effective
having legal authority; binding
having some force or cogency a valid point in a debate
(logic) (of an inference or argument) having premises and conclusion so related that whenever the former are true the latter must also be true, esp (formally valid) when the inference is justified by the form of the premises and conclusion alone. Thus Tom is a bachelor; therefore Tom is unmarried is valid but not formally so, while today is hot and dry; therefore today is hot is formally valid Compare invalid2 (sense 2)
1570s, "having force in law, legally binding," from M.Fr. valide, from L. validus "strong, effective," from valere "be strong" (see valiant). The meaning "supported by facts or authority" is first recorded 1640s.