Type 1 : insists that the user provide them with specifications for their system. They sit waiting for this document and when it eventually arrives they ignore it and the users and write something that doesn't meet the requirements anyway. Eventually these software developers either get put in a corner and ignored or sacked. They usually moan that users are a pain.
Type 2 : they discuss the requirements with the users and draw up a spec themselves. In constant dialog with the users they convert the requirements into code that implements a system that approximates to what is required. Its never perfect but it does the job. These software developers get respect from their user community and get promotion. These software developers while finding users a challenge to deal with, actually like helping them.
My advice is to do what your boss suggests and write the spec yourself and talk to the users.
When I interview software developers I have some major turn offs. The first is developers who complain that users are a pain and those that complain that the system failed because there was no spec or it was badly written. As an employer you need software developers who are pro-active and talk to their user community. Ones who wait passively for users to make up their mind are not worth hiring.