Use of [Emacs##] tags to specify Emacs Version

Question

On SO there are tags for emacs23,emacs24 due to version differences in Emacs.

How do we want to deal with such tags here (particularly since we could end up with emacs24.3,emacs24.4,etc)?

What version are we assuming is default when answering questions?

This can ultimately become an even greater issue with backwards-incompatible changes going forward (inclusion of package.el was one such) leading to older questions not necessarily indicating that they are not necessarily valid with the current release.

Answer 1

Interestingly, for such tags I would see even greater value in tagging the answers rather than the questions. I strongly suspect that the answers would generally tend to favor the latest Emacs versions (and maybe even unreleased ones, which is what 24.4 is), without fully realizing it. Which might prove quite useless for the person who actually asked the question.

Another problem is, as you mention, the Emacs minor versions. We clearly cannot rely on the fact that there's such a thing as a consistent Emacs24: 24.3 and 24.4 both introduced very fundamental changes that are incompatible with what was in place for 24.1 and 24.2. We're far from following semantic versioning, as acknowledged by Stefan

Answer 2

Here's my opinion. Version tags are fine and, as @Sigma mentions, they should include minor version (emacs-24.1, emacs-23.4, etc).

We should use this tag to ask about things specific to an Emacs version (what's new in it, bug/error that only happens on it). A lot of these tags will end up being applied after the question is asked, because the asker might not know the question is specific to a version.

We should not use this tag to ask about specific features, even if they are new features. These questions should be tagged according to the feature.
For instance, package.el was introduced in 24.1, so questions about it are somewhat version specific. Still, they should not use a version tag, they should just be tagged package.el. After all, package.el could well be used with an earlier Emacs, not to mention you'd need 4 different version tags and then they'd become out dated once new versions are released.

Answer 3

Tag Emacs, which abstracts from version and implementation/platform, is clearly not needed. (If this were not an Emacs site, it would be useful.)

All of the following should be possible tags:

• GNU-Emacs or XEmacs or ZEmacs or..., which concerns only a particular implementation/platform

• Emacs-24 (and Emacs-20 etc.), which concerns only a particular series of versions of (GNU) Emacs (Emacs 24.1, 24.2, 24.3,...)

• Emacs-24.4, which concerns only a particular version of (GNU) Emacs

The practices to encourage should be:

• Use the tag that is the most general that applies. So if something applies to all GNU Emacs 24 releases but not to later or earlier releases, and not to Emacs in general, then use Emacs-24.

• When something applies to GNU Emacs release N and later, just specify the release applicability in the text. You could use tag Emacs-24, but you would risk making your question or answer out of date at some point.

The tag definitions should make it clear that Emacs-N refers to GNU Emacs release N. For Emacsen other than GNU, the text in the post should specify release names/numbers as needed. We should not bother with tags for specific non-GNU Emacs releases.

The only reason for that last convention is convenience: GNU Emacs is what the vast majority of users use today. If that changes somehow in the future, then this can be revisited.

If others think that all GNU Emacs tags should explicitly include the prefix "GNU-" then I'm OK with that too. But I think it will just inconvenience users.