I want to add some different transaction information in my chain, but i can't find where can i add it.
The different transaction information is about other chain.
for example:
Mr.X sell goods to Mr.Y (the goods is a coin in my chain, call G-coin)
Mr.X will be receive 100 A-coin
I want to record something with this transaction information,
in G-coin chain will be record A-coin Block number, and A-coin chain will be record G-coin Block number.
How can i add this information in block?