What They Mean:
Taken from the NDMS website FAQ's

Advisory: You have received word of a disaster, possibly by way of TV coverage. No response is indicated at this time. You will not receive any official word from NDMS about the disaster.

You should:

Take no action
Continue to monitor situation via radio or television coverage.

Alert: Your Team Commander has received official word from NDMS of a possible need for response team activation to a specific disaster. You will receive official information from your Team Commander, Deputy Commander, Administrative Officer or NDMS placing you on alert.

You should:

Make yourself available via phone, fax, pager
Transfer information as requested
Assess the readiness of your personal gear, for the specific disaster area climate and make necessary changes
Insert last minute items into your deployment pack
Make necessary personal preliminary preparation for deployment
Notify employer of the Alert status
Acquire any prescription medication (two week supply)
Withdraw enough money, some in cash and some available with a credit/debit card etc. for you deployment (you will not receive pay until you return home)

Activation: Your Team Commander has received official word from NDMS that Activation (deployment) of some or all of his or her team is necessary. You will receive instructions from NDMS regarding travel and depart home on fairly short notice. DO NOT CALL, FAX OR EMAIL YOUR TEAM COMMANDER, DEPUTY COMMANDER OR ADMINISTRATIVE OFFICER UNLESS ASKED TO DO SO. THEY ARE VERY BUSY DURING AN ACTIVATION AND WILL CALL YOU WITH DEPLOYMENT DETAILS.

You should:

Report for travel when and where directed and keep all receipts
Take your "Deployment Pack"
Upon arrival at the disaster area, the Team Commander will immediately report to the Management Support Team Commander (if a member is traveling on his or her own, report directly to the MST Commander)
Perform your assigned duties as a team player
Comply with the chain of command and policies adopted for the "disaster specific" operation
Be responsible for your well being and if possible, keep in touch with your family
Comply with the NDMS Code of Conduct
Attend briefings as directed
Remember team operational activities (I.e. DMORT) deal with sensitive issues
Post Activation: Returning home.

You should:

Attend any debriefings facilitated by your Team Commander-For DMORT teams it is mandatory to attend debriefings
Follow through with any administrative details with your Team Administrative Officer