Is there a metaphor to say "it's named this way for a reason"

I was wondering is there an English or American metaphor or phrase to say it has been called this way for a reason? Suppose I want to say this

The private key is called private for a reason!

Is there an expression that sounds more like a native!

The clue is in the name.

A fixed expression (too transparent to be an idiom), with over 8.5 million hits on Google.

Some examples:

• The Clue is in the Name. Was ever a whisky better named than Rosebank? It has always been considered a fragrant single malt .... [Rosebank Distillery]

• John West No Drain Tuna: The clue is in the name [John West]

• 'Private member club'. The clue is in the name. Private clubs, and hence club dining outlets, are not open to the public. Privacy – perhaps better expressed as exclusivity – is one of the primary reasons members join in the first place .... [T Tassitano; RSM] [tweaked]