This page contains examples of the sign format.
Selling items
If Rachel, being the entrepreneurial type, wanted to sell iron swords at $12.50 each:
Rachel
1 isword
$12.50
This means Rachel will receive $12.50 and the person who clicks the sign will receive an iron sword.
Buying items
Or, if Peter, the up-and-coming master builder, wanted to buy wooden planks at $2 for four:
Peter
$2
4 plank
Peter will receive 4 planks and the sign clicker will receive $2.
Donations
Or, if Tim was feeling poor and wanted donations:
Tim
nothing
$5
Freebies
Or, if Violet was feeling rather kind and wanted to give free dirt:
Violet
64 dirt
free
Global signs
Or, if Wally the admin needed to get rid of slimes:
[Global]
$0.25
1 slime
Damage values
One day, Bob found a huge pile of pink wool. He decided to sell it.
Bob
8 wool 6
$1
Since version 11, you can specify the item name directly:
Bob
8 pinkwool
$1