### Question
What is the definition of usable space?


### Answer
The definition of **usable space** is as follows in *47 U.S.C. § 224*:

> the space above the minimum grade level which can be used for the attachment of wires, cables, and associated equipment

#### Citation:
  - *47 U.S.C. § 224*
  - Heading: **CHAPTER 5-WIRE OR RADIO COMMUNICATION > SUBCHAPTER II-COMMON CARRIERS > Part I-Common Carrier Regulation**

