Related Clues:
- 18 Across material
- Letters, catalogs, etc
- Letter distribution on a base
- "Junk" that goes third-class
- __ lab
- Lancelot's strong suit?
- 'You've got --'
- Postman on the phone
- Molecule for which Linus Pauling proposed a triple-stranded structure
- Crime-lab material
- 'CSI' material
- Common delivery
- Some plane cargo
- A lot of it is first-class
- Evidence in a paternity case