השבת אבידה
אם מצה אבידה אין סימן אין להוכיח את הדבר
מקום שבשבת אבידה בתורה
The example the Mishna uses of a lost item. If you find it you must make a effort to return it to your brother.
This object has no sighn
If it is lost you can keep it because there is no way to tell who it belongs to.
Shloshet Rgalim
If you find an object in israel you take it to yerushalayim on the shloshet rgalim. Everyone goes to israel in this time. If you find it in Jerusalem you must look for the neighbors in the area.
Yeoosh: This means you've given up all hope of finding your object
Hachrazah
This is when the finder of an object advertizes that he found something.