Inventory on hold
 

I going to book an OW award ticket with AA miles, I know that I can put the trip on hold for 14 days.

If the first part of the trip is say available now, can I hold those flights and put in dummy flights for the rest of the booking then change the dates and flights of the dummy part at a future date (within the 14 days)?

I think I have found the answer to my own question by doing another search and using the word dummy. I feel like one at the moment.

I would say the answer is Yes.

The answer is specific to AAdvantage (each FFP has its own rules). Perhaps this could have been posted on AAdvantage forum?

Yes, but there is no need. Prior to ticketing, it can just end wherever.

I routinely book award tickets in this way. I call 330 days out, hopefully grab that flight, and leave it at that. 330 days before the next segment, I call to try and grab that. (The only hassle is that the AAgents have to change the award category each time I add flights. They say they can't book anything without having the proper award category there.)

But don't you run the risk, between the cancellation of the first award and the booking of the second, even if done in seconds, of one or more of the award seats going back into paid buckets (not becoming available again as an award seat)?

Outbound sector is not cancelled upon adding the return (subsequent) sector - it is added to the itinerary and then ready to ticket.

The OP is about a oneworld award. Does the above work in this case?

There shouldn't ever be any cancellation -- just keep adding segments to an existing record. Then, when the last segment is added, ticket it.

The AAgents do need to modify the record to change the type of award that it says will be used, but as far as I know that doesn't cancel anything.

Yes -- all but one of the awards I've booked this way have been OW awards.

When the AAgent needs to change the award type it is to increase the number of miles I need to spend. Sorry for not making that clear.

The fact that the AAgent needs to put in an award type is a technicality. It doesn't have to be defined as one and ticketed until just that - ticketing. Prior to that it is just a reservation and can be one segment, two or however many and the checking against specific award rules doesn't happen until ticketing.