The ‘My previous work details’ field indicates the industry that the candidate was previously from, and the relationship he/she had with the superior in their current & previous company.
& if they could work well in previous work environment. Should the candidate be unwilling to complete this (assuming information was available), it also indicates that they have no confidence or a prior negative experience. A candidate who has nothing to hide would be more than happy to complete the fields required. Such information becomes soft facts that can affect your decision to accept or decline this candidate