joint defense

u could use joint def to 1 of ur nearby castles or a guildmate's castle..even if they spy the castle wer u sent ur army,the report will only display the details of the castle and the amy in there(not included the army u sent by joint def..so if u used joint def and send it to a castle without any units,wen sm1 spies,they wont see any units there..hope it helps

by a secret informer:)