הלכה על גיטין 1:6

Rav Schachter explained to me that a testator merely needs to sign the shtar chatzi zachar - no further action is required. It takes effect even though the beneficiary of the debt is unaware of it because of the halachic principle “Zachin l’adam shelo b’fanav” (one may acquire something beneficial on behalf of another individual even if the latter is unaware of the acquisition; Gittin 1:6). The heirs, both halachic and non-halachic, also need not be aware of this document, Rav Schachter explained, as all of the transfers happen automatically. Whether they know it or not, the non-halachic heirs receive the money as a result of the need to relieve the halachic heirs of the conditional debt, not as a proper inheritance. The document attesting to the conditional debt is needed only to uphold the halachic validity of the secular will if the halachic heirs challenge it in beit din; the will can be executed even without the heirs’ awareness of the document’s existence. The document itself, though, must be deposited with someone other than the testator in order for the acquisition of the debt to take effect, since the process of zachin l’adam shelo b’fanav involves one person handing something to another person to acquire on behalf of a third party.