Symbol 5569 from IEC 60417 - Title/Meaning: Locking, general Function/description: To identify on a control that a function is locked or to show the locked status.
Additional information: 
Published in: Supplement N, 1995;3C(Central Office)192
Own work using: iso.org/obp/graphics/grs/f19d5cfd-5452-4faa-9f09-f5d815c9f37c 200.png
Vectorization:  Mrmw