A Jewish prayerbook (or siddur) is basically (2) — giving the text of the prayers to read for the daily services and other events. However, my understanding is

A Jewish prayerbook (or siddur) is basically (2) — giving the text of the prayers to read for the daily services and other events. However, my understanding is that this note doesn’t form part of the prayers themselves, but merely happened to be written on a page of the prayerbook.