Indo means guiding the living to the correct teachings of Buddha.
Indo has expanded in meaning to be a Buddhist word that also describes the prayers a monk says to the dead after reading the sutra, which is one of the rituals performed at Buddhist funerals. Indo also means the act and the proper ritual of bestowing Buddhist words.
Different sects of Buddhism refer to different parts of the funeral as Indo.
There is a sect that does not perform the Indo ritual.
Examples of references from the sutra.
Giving guidance to follow the correct teachings of Buddha. (Dainichikyosho, 20 volumes)
Characteristics of various sects.
Shingon Sect. The Shingon Sect has rules on Indo. The teacher bestows the secret inmyo (sign) and pours water onto the head of the follower in accordance with the rules of Indo.
Jodo Shinshu sect (the True Pure Land Sect of Buddhism)
Their version of teaching does not include Indo ritual.