Given the 2 jobs, the $oldjob contains containing the current job information,
The new job contains and $newjob containing the job after its modification is applied. The modifications are applied, and the $user which is the name of the user requesting the modification (new in 6.10), the function must return 1 if the change modification request is accepted and or 0 if the change it is to be rejected.
Qube release 6.10 added $user. It can be used, for example, to allow modification of a job's priority from 3000 to 100, to certain users only.
Note that, qb_approve_modify() is NOT applied to request from admin users-- they are allowed to do any modification to any user's jobs, always.
Note also that ordinary users are only ever allowed to modify their own jobs, and that this job filtering is done before qb_approve_modify() is applied. So, in other words, even if qb_approve_modify() is written so that a specific user is allowed to modify others' jobs, it won't work as expected.