Symbol 2012 from ISO 7000 - Title/Meaning: Numeric lock Function/description: To identify the control to select and remain in the numeric mode of the keyboard.
Additional information: 
The meaning of the symbol depends on its orientation.
Own work using: iso.org/obp/graphics/grs/82a0ea6e-e925-4309-bfc0-e1cbdc833df2 200.png
Vectorization:  Mrmw