http://www.syndie.i2p/manual.html
Otherwise,
use the indexed channel read key //set --cancel $uri[,$uri]* Include instructions to cancel the given posts set --messageId ($id|date) Specify the post's messageId, or a random ID based on the current date set --subject $subject Specify the post's subject set --avatar $filename Specify the (32x32 pixel PNG) avatar to bundle with the post set --encryptToReply $boolean Encrypt the post to the channel's ElGamal reply key so only the channel owner
can read the reply. set --overwrite...