Confusing documentation about tags

[GovindarajanNagarajan-TomTom]

Hi,
The Readme, while detailed, IMO, misses the core point of how metadata-action deciphers the output tag. I am running into some issues using this action locally in our team's repo and would like some clarifications.

The example in the README.md provides the following tags definition:

          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=sha

I am afraid I don't understand this very well.

1. Is the type of the output tag the ref , if the event that triggered this workflow is a push to the branch ?
2. why are there 2 patterns specified for semver ?

            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}

The docs seem to imply that semver is the type of tagging that happens by default when a new tag is created. Is it true ?
If so, why are 2 patterns specified ? Are they both used, or is it more of a prioritization over another ?

And is there an inherent prioritization to the rules defined for the tags ? If so , it is ascending or descending ?

[crazy-max]

1. Is the type of the output tag the ref , if the event that triggered this workflow is a push to the branch ?

ref tag type is explained here https://github.com/docker/metadata-action#typeref. You also have examples of what to expect in the table below:

This type handles Git ref (or reference) for the following events:

• branch ; eg. refs/heads/master
• tag ; eg. refs/tags/v1.0.0
• pr ; eg. refs/pull/318/merge

Event	Ref	Output
pull_request	refs/pull/2/merge	pr-2
push	refs/heads/master	master
push	refs/heads/my/branch	my-branch
push tag	refs/tags/v1.2.3	v1.2.3
push tag	refs/tags/v2.0.8-beta.67	v2.0.8-beta.67
workflow_dispatch	refs/heads/master	master

Ref is set by GitHub Actions depending on the triggered Event.

2. why are there 2 patterns specified for semver ?

Also explained in https://github.com/docker/metadata-action#typesemver

pattern defaults to Git tag if empty.

The docs seem to imply that semver is the type of tagging that happens by default when a new tag is created. Is it true ?

Yes

If so, why are 2 patterns specified ? Are they both used, or is it more of a prioritization over another ?

Because you might want to push multiple tags with one being <major>.<minor> and another one <version>. This is useful to push <major>.<minor> tag so user consuming your image can just use v1.0 without worrying about updating the image ref when patched releases are pushed (v1.0.1, v1.0.2, ...).