Any plastic bottle after drinks is a PET (1) bottle. Sometimes it might be without mark (triangle and letter and/or number). PET (1) can be defined in bottles by arched circle in the middle of the bottom

1.
Empty the bottle from a liquid

2.
Rinse well, especially if it contained milk, sweet or alcohol drinks

3.
Jam the bottle as a much as possible

4.
You can leave the label and cap on the bottle

