The Crop Mastery Billboard aka Crop Mastery Sign Billboard was originally released on the January 10th, 2012 for the storage of crop mastery signs.
It can store crop mastery signs the way storagebuildings such as barns and sheds do, but unlike these which require a Barn Raising to increase the number of items they can store, the storage capacity is increased by collecting building materials, and when fully expanded it can hold up to 5,000 items.
HOW IT WORKS
Crop Mastery Sign Billboard - HOW IT WORKS!
Crop Mastery Sign Billboard - Initial Notification Message