PCB 마킹 의미

L/C/R/U 정도만 알았는데 별게 다 있네..

U는 inseparable assembly... U가 없는데? 

[링크 : https://blogs.mentor.com/tom-hausherr/blog/tag/reference-designator/]

    [링크 : http://electronics.stackexchange.com/questions/25308/what-do-the-pcb-markings-mean]

[링크 : https://en.wikipedia.org/wiki/Electronic_symbol]

혹시.. IC에서

A circuit in which all or some of the circuit elements are inseparably associated and electrically interconnected so that it is considered to be indivisible for the purposes of construction and commerce.

Circuit 중... U 인가??!?!?

[링크 : https://en.wikipedia.org/wiki/Reference_designator]

unspecified -_-

[링크 : http://electronics.stackexchange.com/questions/25655/why-is-u-used-for-ics-on-circuit-diagrams]