Define the problem that this decision solves.

Provide details why this is relevant for the project and why it should be documented to be referable later.

Provide details what implications this decision has on the project.

Illustrate the functional and non-functional-requirements that constrain the decision.

Provide details what other drivers are relevant for the decision.

Provide details which risks are involved for the decision.

Provide details which assumptions have been made to make the decision. It is assumed that assumptions cannot be proven else this would be a requirement or not mentioned if proven invalid.

Describe strategies how the given assumptions can be proofed or refuted?

List the risks you assume this assumption has.

Define what has been decided to do. This should be a brief statement since this is also rendered in the index document.

State what reasons led to the decision.

Provide details what implications this decision has on the project.

Specify the date of the decision.

Provide a list of stakeholders that made the decision. If there is uncertainty about why this decision has been made, these stakeholders may provide additional information at a later time. Consider then to include this information in this document.