There is very scant documentation on RelatedInformation and it isn't currently used by any of the analyzers in golang.org/x/tools, but it corresponds to the concept of the same name in the https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#diagnostic, and gopls connects them.

This proposal seems reasonable to me.

Thank you for your attention and looking forward to it.

It's too bad we dont use json to write this json, but we should use a consistent casing for the names, whatever it is. The example says posn/message (lowercase) but then Related (uppercase).

Agreed, will make the case consistent.

This proposal has been added to the active column of the proposals project
and will now be reviewed at the weekly proposal review meetings.
— rsc for the proposal review group

Based on the discussion above, this proposal seems like a likely accept.
— rsc for the proposal review group

Proposal is to add a new field “related” (lower case) in the JSON object describing each error:

{
    "package_name": {
        "rule_name": [
            {
                "posn": "main.go:34:2",
                "message": "error msg",
                "related": [
                    {
                        "posn": "main.go:34:2",
                        "message": "relatedinformation"
                    }
                ]
            }
        ]
    }
}

Change https://go.dev/cl/556820 mentions this issue: go/analysis/internal/analysisflags: add RelatedInformation JSON

Nice！Waiting for release

No change in consensus, so accepted. 🎉
This issue now tracks the work of implementing the proposal.
— rsc for the proposal review group

Proposal is to add a new field “related” (lower case) in the JSON object describing each error:

{
    "package_name": {
        "rule_name": [
            {
                "posn": "main.go:34:2",
                "message": "error msg",
                "related": [
                    {
                        "posn": "main.go:34:2",
                        "message": "relatedinformation"
                    }
                ]
            }
        ]
    }
}