Mandatory
This field specifies the designated maturities of the rate source.
For an ISDA Master (Type in field 77H = ISDA), this field specifies the Designated Maturity as per ISDA definitions.
Period-From and Period-To must be specified using one of the following codes (Error code(s): T48):
This field specifies the tenor for the interest rate. Eg, a deal that starts in 3 months and ends in 9, has a 6 months tenor; in this case 38G contains 6M/6M as it is the 6 months rate; here both subfields have the same value.
For interpolation, this field specifies the two designated maturities.
When there is no interpolation, Period-From and Period-To must be the same designated maturity.