Play Diagrams

Hey, I was wondering what the symbols on the play diagrams mean?
square = I'm assuming this means the player is in man coverage?
circle = I'm assuming this means the player is in zone coverage?
circle with an uneven straight line = zone coverage but not sure what the squiggly line means.
Circle inside a circle = not sure.
Arrows point down = I assume this means the players are blitzing?
The upside down T = not sure.
Thank you.
square = I'm assuming this means the player is in man coverage?
circle = I'm assuming this means the player is in zone coverage?
circle with an uneven straight line = zone coverage but not sure what the squiggly line means.
Circle inside a circle = not sure.
Arrows point down = I assume this means the players are blitzing?
The upside down T = not sure.
Thank you.