- Update the local keyring with the keys of a key server
- and removes from the keyring the archive keys which are no
- longer valid. This requires an installed wget and an APT
- build configured to have a server to fetch from. APT in
- Debian does not support this command, but Ubuntu's APT
- does.
+ Perform an update working similarly to the <command>update</command> command above,
+ but get the archive keyring from a URI instead and validate it against a master key.
+
+ This requires an installed &wget; and an APT build configured to have
+ a server to fetch from and a master keyring to validate.
+
+ APT in Debian does not support this command, relying on
+ <command>update</command> instead, but Ubuntu's APT does.