There seems to be a bit of confusion about when to use the DME tags, so here's an explanation. Please read though this first post before posting a question, as it might answer your question.
What do DME luggage tags look like, and how do I get them?
DME luggage tags will come in your DME Transportation Booklet. They are yellow in color. On the tags will be a Mickey head with your resort region, your resort name, your name, and a bar code. They are very similar to airline routing tags. When attaching them to your bag, you will attatch them to the bag's handle, just like an airline routing tag.
I got some luggage tags that are blue, and have Tinker Bell. Are these the DME Luggage tags?
No. These are just souvenier luggage ID tags.
Do the DME tags replace standard ID tags?
No. You should ALWAYS tag your luggage with separate ID tags.
I want to use the DME Luggage Service. What do I do?
The first thing you'll want to do is attach your luggage tags PRIOR to checking in at your home airport. If the tags are not on your bags before they get checked by the airline, they will not be taken care of. Once the bags have been tagged, you can bypass baggage claim completely. They will show up in your room automatically.
I do NOT want to use the DME Luggage Service. What do I do?
Throw away your luggage tags. You will need to claim your bags as normal, and take them onto the motorcoach. When you get out at your resort, you will claim your bags again.
Do I need to put my luggage tags on my carry-ons?
No. Your carryons will remain with you, so they will not be handled by Disney.
Do I need to put my luggage tags on any bags that I claim from baggage claim?
No. Once you claim your bags, you will remain in control of those bags. Disney will no longer transport them.
My airline is a participating airline. Do I use the tags for my return trip home?
No. Before you leave Disney, it's a good idea to remove those yellow tags from your bag. If the bag gets misdirected by the airlines at MCO, it will most likely be recognized as a DME bag, and get sent back to the resort.
I haven't gotten my tags yet!
Never fear. You have two options. You can claim your bags like normal, or you can have Disney claim them for you as if you did have those yellow tags. Bypass baggage claim, and go straight to the Welcome Center. From there, give the Cast Member your luggage claim tickets. They will create replacement tags for you, find your bags, tag them, and send them to your resort.
My plane may arrive late. What are the hours for Disney's Magical Express.
Transportation currently runs 24/7.
Inbound luggage transfer has recently changed. There will be no automatic transfer for luggage between the hours of 10pm and 5am. Folks arriving between these hours will need to claim thier luggage prior to going to the Welcome Center, regardless of if they used the yellow tags.