383655dd_s_Relating_to_Security_Futures__Description_of_Offset
[0] 14 Individual stock or narrow-based security index [Initial Margin Requirement] The initial margin required under Regulation T for the long security 10% of the current market value, as defined in Regulation T, of the long security [Description of Offset] 
Short security future and long position in a security immediately convertible into the same security underlying the security future, without restriction, including the payment of money
Final Rule: Customer Margin Rules Relating to Security Futures