What does the "E" next to a song title mean?

[WildboyRow]

Can anyone fill me in on the single letter placed by some of my songs. My name is Don, yet there is an "E" by some of the songs. I'm curious if it is a form of sync with the Ols Ladies account somehow? Her name begins with an "E"

Moderator Edit: Edited title for clarity

[AdamPandora · Accepted solution]

@WildboyRow The red E indicates that a track contains explicit content.

Hope this helps clarify.