Makna informant kira2 seperti berikut:

Ref: http://knol.google.com/k/phil-george/registration-of-births-...
By law, every birth, death or marriage is required to be notified to the registrar of the registration district where the event occurred. The person providing the details for a birth or death is known as the Informant - often the father, mother or relation. The details are entered into a register and stored in the registration office while certified copies are sent to the Registrar General at the General Register Office, London. A copy of the entry - a certificate - is supplied to the informant. ...

Yang bisa menjadi informant cukup banyak - meliputi relation (= seluruh kerabat). Jadi, jika sampai diperlukan "legal sub of informant", itu pasti kasus luar biasa.