Form 11 must be filled by those employees who were covered under PF in their last Organisation. Because once they leave the company they should continue using the same PF Account but most of the employees are not willing to get their PF Fund transfered to the new Organisation, therefore they withdraw all the money and open a new PF account in the new Organisation.
It's instructed from the EPF deparment not to open any new account unless employees want to do so. Form 11 is a supporting document which may be shown to any PF Officer during inspection or PF audit foir answering why his/her new PF account has been opened when he/she had an account already in the last Organisation. It's not submiited at the PF and should be kept in employee's personal file. Also, you should also get it signed by those employees who have worked in the past but never contributed towards PF.