Symbol 5520 from IEC 60417 - Title/Meaning: Subtitle Function/description: To identify the subtitle mode.
Additional information: 
Published in: Supplement M, 1994
Own work using: iso.org/obp/graphics/grs/ef54de63-cd8c-491e-af6e-8392b2ecbf1d 200.png
Vectorization:  Mrmw