Know your job description. If you are asked to do work outside of the scope of the job description, notify the union.
Know the definition of “out of title work,” which must be the basis of any grievance stating that you are doing work outside of your job description.
You can read the definition of “out of title work” here: out-of-title-work-psb-100-3r
LIST OF LOCAL 768 JOB DESCRIPTIONS