Fetching details from the dictionary...

being attached (to); being affiliated (to); belonging (to); going with
attached school; affiliated school
付属の説明書をよく読んでください。
Please read the attached instruction manual carefully.
この大学には付属の中学校と高校がある。
This university has an affiliated high school.
ホテルに付属のプールを利用した。
I used the hotel's affiliated pool.