dead letter

n.

（无法投递的）死信，形同虚设的规定；

复数：dead letters

Dead letter
Dead Letter
Dead Letter?
Dead letter or living document? Ten years of the Code of Conduct for disaster relief
Compliance in the enlarged European Union : living rights or dead letters?
Estonian banking regulation as a “world of ‘dead letters’” – the interplay of Europeanization process and national idiosyncrasies
Emerging crisis of continuing professional education: becoming a dead letter between external pressure and personal incentive?
Plastids better red than dead [letter]
The Dead Letter Office: Archival Records at the Library of the Supreme Court of Victoria
The Problem of Dead Letters: Social Perspectives on the Teaching of Writing
The email murders: Reflections on "Dead"letters
Strictly Shakespeare? Dead Letters, Ghostly Fathers, and the Cultural Pathology of Authorship in Baz Luhrmann's "William Shakespeare...
Dead Letters to Alice - Reachability of E-Mail Addresses in the PGP Web of Trust