E-Commerce Configuration Guide : Site Configuration Settings : Membership Settings : 0PmtTxt
 
0PmtTxt
Key value:
Any text
Description:
Used to allow $0 sales. Use 0PmtTxt to override the default text regarding payment type in e-mail confirmations for $0 sales. You need to provide some text for confirmations with $0 total with 0PmtTxt.
Example:
0PmtTxt = Your membership
See also:
AcctPmtTxt
CardPmtTxt
DWPmtTxt