Depending on your entry point to delegates, the documentation might look a tad confusing at first. For me, it was The delegate type section of the C# language reference. It throws around terms like Action, Func, Events, custom delegate types. Predicate is also related to this topic, and this was what I was looking for.
Let me briefly explain what all those words mean and how they relate to
delegate
. Then I will explain why I was looking into this.
Short teaser: “Named Predicate”, like a Hibernate Named Query.