In a paket.dependencies file, what is the meaning of the operator `==`?

Hello,

If issues are not the right way to ask about this, feel free to close it.

In a project's paket.dependencies file, I found thoses lines:

nuget Microsoft.AspNet.Mvc == 5.2.6
nuget Microsoft.AspNet.Razor == 3.2.6
nuget Microsoft.AspNet.WebPages == 3.2.6

I checked the official documentation without success.
My guess would be that == could fix a version number but to achieve this we can directly write nuget Microsoft.AspNet.Mvc 5.2.6.

What is the meaning of the operator ==?

note that I also posted this as a question on Stack Overflow

Review the linked Paket dependencies-file documentation and the shown paket.dependencies examples, then compare the two version syntaxes mentioned in the question. Update the relevant documentation so the meaning of == and its distinction from the alternative declaration are explicit; the documentation should answer this question without requiring a separate Stack Overflow post.