In the domain name registration process, the purpose of a SMD file is to show that the Trademark Clearinghouse has verified your mark, and that you have met the minimum eligibility requirements to request the registration of domain names during the sunrise period of a TLD.
For example, if your mark is "Example One", your SMD will show that you are allowed to register exampleone. <TLD> or example-one.<TLD>.
Note: A mark (e.g., Example One) is converted into specific domain name labels (e.g. exampleone) that are technically valid in the domain name system, according to a set of matching rules applied by the Trademark Clearinghouse. Your SMD may allow you to request the registration of one or more labels (e.g. exampleone and example-one) depending on the name of the mark submitted.