Hi,
My wife was asked to get me to fill this form too, she was told it was on the BHC website but I was unable to find it for the life of me! It does actuallly state on the BHC website (ISB) that it is not required but the fedex guys insisted that it was important, despite the fact I paid a solicitor to write me one up aswell; it is basically sent to the Department of Work and Pensions.
Found it in the end and faxed it over, you can find it here:-
http://www.ukvisas.gov.uk/servlet/Front ... 8721067523.
Towards the bottom of the page.
I would fill it out again and fax it over just to be on the safe side, these people will want any excuse to prolong the application process!
Good luck!