Type AC cable must be secured within 12 in. of every outlet box, junction box, cabinet, or fitting and at intervals not exceeding 4½ ft [320. 22, which applies when. Part II of Article 770 provides the requirements for cables outside and entering buildings. Of course, if it's entering a building it would necessarily be outside unless it is entering from within another building that shares a common wall. So basically, this is about outdoor cables. It defines a minimum leve e fiber optic cabling extends between buildings. Although the standard covers premises installations, many of the provisions included here ar SI/ NFPA 70, the National Electrical Code (NEC). (FOA) was founded in 1995 to help develop the workforce to build the fiber optic networks to support a rapid expansion in communications and the Internet.