How do you mark code as deprecated in Go?

Add this Comment to your function / struct // Deprecated: FunctionName is deprecated.

Godoc: documenting Go code says this about marking code as deprecated:

To signal that an identifier should not be used, add a paragraph to its doc comment that begins with "Deprecated:" followed by some information about the deprecation.

Here's an example of the syntax (view more here):

// Title treats s as UTF-8-encoded bytes and returns a copy with all Unicode letters that begin
// words mapped to their title case.                                                            
//                                                                         
// Deprecated: The rule Title uses for word boundaries does not handle Unicode              
// punctuation properly. Use golang.org/x/text/cases instead.                 
func Title(s []byte) []byte {  
    ⋮
}
                               

The documentation site pkg.go.dev hides the documentation for deprecated identifiers behind a click of a "show" button.

The staticcheck tool reports use of deprecated identifiers (see SA1019).

The Goland IDE code inspector reports use of deprecated identifiers.