cmd/go: unexpected output with go doc std

go version go1.19beta1 linux/amd64

Does this issue reproduce with the latest release?

Yes

What did you do?

Originally, I was attempting list all standard packages via go list std. I tried to find documentation go help list that confirms the use of "std" as some kind of proxy for listing the standard library. That led me to go doc std.

What did you expect to see?

I expected to see nothing (as its not a package) , or some kind of magic placeholder, or some kind of invalid package error.

What did you see instead?

What I think I see is the first standard library package in alpha order, archive/tar.

~$ go doc std
package tar // import "archive/tar"

Package tar implements access to tar archives.

Tape archives (tar) are a file format for storing a sequence of files that
can be read and written in a streaming manner. This package aims to cover most
variations of the format, including those produced by GNU and BSD tar tools.

const TypeReg = '0' ...
var ErrHeader = errors.New("archive/tar: invalid tar header") ...
type Format int
    const FormatUnknown Format ...
type Header struct{ ... }
    func FileInfoHeader(fi fs.FileInfo, link string) (*Header, error)
type Reader struct{ ... }
    func NewReader(r io.Reader) *Reader
type Writer struct{ ... }
    func NewWriter(w io.Writer) *Writer

Maybe std is meant to be magic, but if its not, it seems that it would documented in go help list and clearer usage with go doc std. I could also just be wrong on its usage (found via some random posts).