It is expected so. In case he is just declaring his just previous employment also, you can accept it. Suppose, if he was employed in more than two companies how can he write all those details? No. Therefore, practically, just previous employment would be sufficient.
The purpose of form 11 is to make sure either of two things, ie, (1) if the new joinee was earlier a member of PF and if yes, he should be given coverage even if his salary is more than Rs 15000 (2) if the new employee was not a member of PF in the past, he can be excluded in the present company also provided his PF qualifying salary exceeds Rs 15000. A person receiving PF pension or persons who have withdrawn the PF are also excluded employees. The form 11 also serves these purposes.
Madhu.T.K