Field help (FRM) 

For Variable bank file types, you can define the variables used in the XML file.

Examples:

[L]MSGID This variable contains the value of the sequence number used. This sequence number is defined in the Sequence number assignment function.

[L]NBPYH This variable contains the number of payments included in the file.

[L]TOTCUR This variable contains the sum of all the payments included in the file without taking currencies or conversion into account.