var flag.ErrHelp

3 uses

	flag (current package)
		flag.go#L101: var ErrHelp = errors.New("flag: help requested")
		flag.go#L1113: 			return false, ErrHelp
		flag.go#L1168: 			if err == ErrHelp {

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)