In calling employer references I ask yes no questions. That way there probably not be a be a problem with disclosure. I won't hire anyone who doesn't give an OK to check previous employers.
Questions are like has he ever been late to work, been late more than once per month, been a discpline problem, had any safety violations, get along with others etc.
I like people that have had cflose to 5 years somewhere recently as it show stability.
I don't like people that complain about their boss, supervisor or crew members. I do take some of it with a gerain of salt becasue I know there are lots of A--hole owners and supervisors too.
I give everyone an employee reliability inventory test from
Other questions are have you ever been in the back of a police car and how many points do you have on your drivers license?