Eiruvin 10:4-5

Eiruvin 10:4

If a window ledge projects into the public domain, the people in the house may still place things on it or remove things from it on Shabbos. A person who is standing in a private or public domain may move an object that is in the other type of domain, though he may not move it beyond four cubits in a public domain (about six feet).

Eiruvin 10:5

A man may not stand in a private or public domain and urinate into the other type of domain, nor may one spit into the opposite kind of domain. Rabbi Yehuda says that if one has detached saliva in his mouth, he may not walk beyond four cubits without expelling it.