IT'S IMPORTANT TO UNDERSTAND HOW REWARD BOOKINGS WORK BEFORE YOU TRANSACT.

1.   Marriott certificates can be used for any reservation that can be booked with points. To search for reward availability simply go to marriott.com and check the box to search "using points".
Marriott hotels are divided into categories. (Cheapest being category one)

What room types can you book?
You can book any STANDARD room that's available at marriott.com using reward points with no cap on the number of points. (standard room means it not an upgraded room. Every hotel lists their rooms differently, In some hotels, the standard room may even include suites)
To check, go to marriott.com and search for rooms. Make sure to check the option "Use Points/Certificates".

If it says:
Redemption - You can book that room no matter how many points it is
Redemption with Cash Upgrade - You can book however, the cert will cover the basic portion you will need to pay the additional cash upgrade fee.
Redemption with Points Upgrade - You cannot book using a certificate

2.   There are a few different types of certificates. Seven/five night certificates are the hotel portion of "Marriott travel packages" that the owner does not want or need anymore (google Marriott packages to learn more about them). Individuals many times buy these packages just to receive the airline miles and don’t end up using the hotel portion of the package. There are also single night certs given to account holders for holding a Marriott brand credit card

3.   A 7/5night-night certificate must be used for 7 consecutive nights. The reservation cannot be split up.

4.   In order to hold the room, you need a credit card. Your card will be kept for incidentals and you won't be charged for the room.

5.   MUST be booked BOOK 30 Days in Advance. THIS IS A TECHNICAL GLITCH WHICH MARRIOTT CLAIMS TO BE FIXING, HOWEVER, ITS MORE THAN A YEAR THAT THIS HAS BEEN AN ISSUE. In order to book with a certificate, reps must create the reservation as a points advance and then attach the cert. Marriott recently made a new rule that reservations made within 30 days aren’t eligible for points advance. If the account, you are booking with has enough points to cover the reservation you can book it as regular points and have the rep detach the points and attach the certificate.

6.   Travel package certs must be booked over the phone. Single night certs can be booked online

7.   The certificate sits on the account holders account and the elite night credits are officially credited to them. There is no way to transfer those stays to your account.

8.   If you are the traveler do not call Marriott reservations. This reservation is in someone else's account and calling may result in his/her account getting audited and the reservation canceled.

9.   The certificate covers the cost of the reservation including tax but does NOT include any resort fees, parking, and incidentals (for example food charged to the room)

10.   It's not possible to entirely remove the certificate owner from the reservation but your name is added as a secondary guest and a special code is added (M8 code) to inform the hotel that this reservation is in fact gifted to you. The hotels are very much aware of this.

You should be able to check-in as you would to a regular reservation with your own ID. You will need to provide a credit card to cover any incidentals, resort fees, and parking fees if there are any.

11.   You cannot add your Marriott account number to the reservation and generally, the hotel will go by the status on our account (which may be silver or gold at the time of check-in) however, it depends very much on the front desk rep at the time of check-in

12. Certs cannot be combined - e.g. you can't combine two 35k certificates to book a 60k room.

13. The "free fifth night" only applies to points bookings, not certificates.

See post #5805 for a history of bid/ask on these 1/5/7 night certificates of different levels