This article outlines the database structure for the MMv4 ptcs_item database table.

• id
  Primary Key of the table.
  int(10) | unsigned | auto increment | primary key | indexed
  
• display_order
  The order in which the UpSell / DownSell products will be displayed in the storefront to the customer.
  int(10) | unsigned | indexed
• ptcs_id
  This is the id reference to the ptcs DB table.
  int(10) | unsigned | indexed
• thread_id
  Specifies the which thread this UpSell/DownSell element of the chain represents.
  char(1) | indexed | default: A
  
• pid
  The system ID (SID) number of the Product in which will be displayed for this UpSell/DownSell element.
  int(10) | unsigned | indexed
• accept_item_id
  This is the system ID number (SID) of the product that will be displayed to the customer if they choose to purchase the displayed UpSell product in the storefront.
  int(10) | unsigned | indexed
• skip_item_id
  This is the system ID number (SID) of the product that will be displayed to the customer if they choose to skip the displayed UpSell product in the storefront.
  int(10) | unsigned | indexed