add-ins Adding an entry to a solutions GlobalSection(ExtensibilityAddIns) section

I want to load an addin form a solution but cannot find the correct syntax for entries within the section.

My addin is called 'setbuildenv' and I want specific solutions to load it so that tier build environment can be controlled.

What is the entry I have to add to the GlobalSection(ExtensibilityAddIns) = preSolution and/or GlobalSection(ExtensibilityAddIns) = postSolution sections of an sln file?

regards

MikeBr47