FCC認證標準Part15 B中B代表的意思

準確的說 FCC Part 15 B應該是FCC Part 15 Class B（B級數字裝置）。
Class A和Class B的定義：
Class A digital device－A級數字裝置
A digital device that is marketed for use in a commer cial, industrial or business 
environment, exclusive of a device which is marketed for use by the general public 
or is intended to be used in the home.投放市場供在商業、工業或商務環境中使用的數字裝置，但不包括投放市場供一般公眾或家庭使用的裝置。
Class B digital device－B級數字裝置
Class B digital device. A digital device that is marketed for use in a residential 
environment notwithstanding use in commercial, business and industrial 
environments. Examples of such devices include, but are not limited to, personal 
computers, calculators, and similar electronic devices that are marketed for use by 
the general public. Note: The responsible party may also qualify a device intended 
to be marketed in a commercial, business or industrial environment as a Class B 
device, and in fact is encouraged to do so, provided the device complies with the 
technical specifications for a Class B digital device. In the event that a particular 
type of device has been found to repeatedly cause harmful interference to radio 
communications, the Commission may classify such a digital device as a Class B 
digital device, regardless of its intended use。

　下面是FCC PART 15目錄章節內容：
Subpart A – General（一般要求）
Subpart B - Unintentional Radiators（無意輻射體）
Subpart C - Intentional Radiators（有意輻射體）
Subpart D - Unlicensed Personal Communications Service Devices
Subpart E - Unlicensed National Information Infrastructure Devices
Subpart F – Ultra-Wideband Operation
Subpart G – Access Broadband Over Power Line (Access BPL)

   投放市場不僅供在商業、工業或商務環境中使用而且要在居住環境中使用的數字裝置。這類裝置的例子包括（但不限于）：個人計算機、計算器以及其它投放市場供一般公眾使用的類似電子裝置。注：職責部門也可以把投放市場以供商業、工業或商務環境中使用的裝置定義為B級裝置；事實上FCC也鼓勵這一舉措，只要該裝置能滿足B級裝置的技術規范。若某類型裝置反復地對無線電通訊產生有害干擾，則FCC可能會將之歸為B級數字裝置而不管其用途如何。