Symbol 6005 from IEC 60417 - Title/Meaning: Pulse background Function/description: To identify the control of pulse background.
Additional information: 
Control is identified by one of letter chosen in IEC 60974-1, Table L.1.
The meaning of the graphical symbol depends on its orientation.
Own work using: iso.org/obp/graphics/grs/febb834a-6541-4039-adf0-326316379bde 200.png
Vectorization:  Mrmw