This packet is used by the Secondary client to halt a file search that is being performed by the currently connected Primary host.

This is the packet format

[0x1775][ Packet Data Length : 2 ][ Search ID/Counter : 4 ]

This packet is automatically sent when the "Stop" button is depressed in the Search window.
The field marked "Search ID/Counter" is unique to each individual search and thus halting any specific search query is pretty simple.