Stores BNU files until they can be delivered.
The /var/spool/uucppublic directory is the public directory for the Basic Networking Utilities (BNU) facility. One of these directories exists on every system connected by the BNU utilities.
When a user transfers a file to a remote system or issues a request to execute a command on another system, the files generated by these BNU commands are stored in the public directory on the designated system until the destination directory is ready to receive them. (A user can also specify a destination other than the public directory when issuing the uucp, uuto, or uux command.) The transferred files remain in the uucppublic directory until they are removed manually or automatically.
All spooling directories are dynamic, including the public directory. Depending on the size of your installation and the number of files sent to the local /var/spool/uucppublic directory by users on remote systems, this directory can become quite large.
The uudemon.cleanu command, a shell procedure, cleans up all the BNU spooling directories, including the public directories. Use the uucleanup command with the -sSystemName flag to clean up the directories on a specific system.
The uuclean command, uucleanup command, uucp command, uudemon.cleanu command, uuto command, uux command.
Understanding the BNU File and Directory Structure in AIX 5L Version 5.2 System Management Guide: Communications and Networks.