SN74AHCT00: Unspecified V_IN to V_DD relation -- unpowered part

Hi,

I need to add enable function to a circuit based on an 74AHCT00. The trick is that the chip will not be powered most of the time and I don't want to power it with the enable signal through some internal anti-ESD structures. Can it be done legitimately without adding external components? The problem is that the datasheet specifies both max. V_DD and V_IN in absolute terms, but not the relation of V_IN to V_DD. In other words, what would happen if V_IN=5V and V_DD=0V?

Best regards, Piot