Final answer:
Cables in accessible attics require guard strips when run across rafters or studding to protect them from potential damage.
Step-by-step explanation:
Cables require guard strips in accessible attics when they are placed across the face of rafters or studding, in which the cable is running perpendicular to the framing members. The guard strip is a protective measure used to prevent the cables from being damaged by any surrounding activity or by contractors and homeowners who may not see the cables while moving through the attic. This is especially important in areas that are subject to work traffic or where cables may be vulnerable to impact or disturbance. The National Electrical Code (NEC) specifies the use of running boards or guard strips to protect cables in such spaces.