Place your cursor over Reference Data and left click on the sub-option Job Prerequisites.
A screen will appear with the top portion being display only of the jobs available in the IQS database accessed by a drop-down list.
At the bottom of the screen you will see "Experience prerequisites for selected Job" and "Training prerequisites for selected Job". That is where you will add, edit, and delete information from both of those tables.
Select the job that you would like to delete experience or training prerequisites from by left clicking on the Drop-down list button 
.
The prerequisites will appear in the lower boxes.
Find the experience or training prerequisite that you would like to delete and left click on the Delete button 
on that line.
A dialog box will appear for you to choose either 
to delete the prerequisite or 
to not delete.
If the item you are trying to delete is associated with any of the data in the database IQSweb will not allow you to delete the data.