Take for example https://musicbrainz.org/release/5b0c80bc-e570-4bb3-a9cb-ccec2bbd7255/cover-art
An editor added a barcode to this release in edit https://musicbrainz.org/edit/67247271
although there is no visible indication on the medium scans.
Shouldn’t in this case the “This release does not have a barcode” checkbox be check-marked ?
There is no barcode, so that editor is clearly in error. They seem to be making up barcodes based on a maths forumla.
As far as I understand, the barcode needs to be on the cover. The MB database is about identifying a release. By adding that barcode then someone will decide that this is not their release.
I notice Discogs also does not list a barcode.
Maybe he has a different catalogue listing them? But that would not be part of the data to upload as it is clearly not on the “LP cover as I hold it in hand”
The example edit is a 1973 release; bar codes were first used on products in June 1974 so it is impossible for a 1973 release to have a bar code.
But still the main question remains: Does a release need to have a VISIBLE barcode on the UPLOADED medium scans (to prove it) to qualify as HAVING a barcode in MusicBrainz terminology ?
Instead of uploaded scans, reference URLs to prove would also be perfect.
Also a clear statement in the syle guide for barcode at https://musicbrainz.org/doc/Style/Release would be useful.
The barcode could be on the shrink wrap.
edit: imo that would be a valid barcode, esp since it might help to find the release online
A shrink wrap with the barcode would be fine too as long as there is proveable scan or reference URL to it.
Or if the trustful editor says they see it on release in hands.
Here the editor says it comes from a guess, so it’s wrong by default.
Why do not upload it then 
You have to have a scanner and some time to scan.
I have only scanned about 1% of my added releases. 
… or some kind of smartphone 
How do you do that with a smartphone?
With Office Lens?
I used it for some documents actually, it’s quite useful.
But never thought of it for scans for CAA.
I mean … better than nothing … you can always delete it later when some real scan is handy.
Btw. thanks for a nice use case when searching with the MB search interface
Bar code or no, the editor in the OP’s link is a bit unhinged. They called me all sorts of insults, and then advised me to follow the Code of Conduct. I’ll concede that my post had a tinge of snark, but I don’t think it warranted a nuclear response.
I have also added barcodes from a generally reliable source (e.g. discogs) even if I have not scanned (or even seen) them myself.
I’ve made a note of them, but please do report editors that go off the hinge like that. I won’t be there to see all of them.