When you share a printer in Windows NT, the spooler creates a thread that broadcasts a message to all Windows NT print servers. Each print server adds the new print share name to its local printer browse list. In addition, each print server rebroadcasts the list of its local printers to all print servers every 10 minutes. A large number of print servers can generate extensive network traffic. You can disable the browse thread on a print server so it will not notify other print servers of the existance of your printers. Of course, when you do, it does not show up to your users in the printer browse list.

Hive: HKEY_LOCAL_MACHINE
Key: System\CurrentControlSet\Control\Print
Name: DisableServerThread
Type: REG_DWORD
Value: 1

Related:
Q181734 - Windows NT Print Browsing Architecture.
Q131902 - Printer Browse Thread May Cause Extensive Network Traffic.

Printer Tips:

Improve print spooling performance
RAW data mode
Print to a file
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Add Printer Panel icon to Windows NT Start Menu
Restrict the ability to add print drivers to Administrators and Print Operators
Hide shared printer
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Submit print jobs to wait afterhours to print
Print Server Migration Utility
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Set how long the port thread waits before giving up
Control printer popup messages
Printer Available Broadcasts
How to install a network printer only once for all users of the NT workstation
HP Web JetAdmin
Allow Print Operators to add a printer
Drag and Drop Printing
Add a printer failed with message "Operation could not be completed. The RPC server is unavailable."
Don't Get Notified When Remote Documents Are Printed

Start here to study networking NT style.