Charles Lindberg
This is Daniel's name for his parakeet. Charles Lindberg is a symbol of Daniel's love for flying, so much so that everything in his life has to do with it.
Snood
Snood is Daniel's nickname which he got as a kid. Though it is used often, it is also a symbol of how the other boys just don't understand him enough to call him by his real name.
Pass--Motif
Daniel is given a pass multiple times in the plays first Act. He uses it in order to practice his flying during class time. It shows that he is not part of the class in a normal way. He exists outside the bounds of the rules everyone else must abide by.
Stubborn
Daniel is a stubborn young man. This is a symbol to Richard that he has great will, in that anything he puts his will to he will achieve. And for Daniel that is flying.
Great Air Disasters
Richard is reading a book suggested to him by Daniel called Great Air Disasters. This is a symbol of Richard's working to understand Daniel and to be his friend.