The borrowed instrument

Text: an original contemporary personal account-style practice extract.

Before taking the borrowed clarinet home, I checked its numbered label against the loan form. The teacher then showed me where the cleaning cloth belonged in the case. I did not play the instrument until the next lesson, because the mouthpiece needed a replacement fitting. At home, I found space for the closed case on a shelf above the dog’s bed. My brother wanted to try a note, but I explained that borrowing something meant following its instructions, not merely promising to bring it back.

From the extract, identify one check the writer made before taking the clarinet home.