As far as I know, there is only one 12.04-related tag: 12.04.
Also, 12.04 (by itself) EOLed on August 8, 2014. 12.04.5 EOLs in April 2017.
As one is off-topic and the other is on-topic, how do we know the difference between the two? Do we just assume that it's 12.04.5? What do we do?
12.04 is not end-of-life (or off-topic) in the usual sense.
On the one hand, someone having problems installing from, or working in the live environment of, non-point-release media (or media from earlier than the current point release) should be referred to the point release ISOs, which contain updated packages that may fix some problems. Even that is not really an issue of site scope; it's just a good idea to try with updated packages when you're having problems.
But any pre-12.04.5 installation of 12.04 becomes 12.04.5 automatically when it's updated.
The the difference between earlier and later point releases in an installed system is merely one of patchlevel, with one interesting exception.
The exception is old HWEs. When people say old point releases of 12.04 are end-of-life, usually they are talking specifically about the HWEs associated with those versions.
Hardware enablement stacks (HWEs) for old point releases are end-of-life and questions about problems with them (other than how to upgrade them or stop using them) should likely be considered off-topic. I believe the EoL status of old point releases' HWEs are the reason EoL dates for 12.04.1-4 are listed on the releases page:
You'll notice that these dates are specifically given for HWE, and not for the point release as a whole.
LTSEnablementStack explains what HWEs are. Basically, they are officially supported kernels backported from newer Ubuntu releases, provided mainly to support newer hardware/drivers.
The 1204_HWE_EOL wiki page1 explains how and why HWEs become end-of-life (emphasis mine):
What is HWE?
Hardware Enablement Stacks (HWE) are incorporated into installers for select Ubuntu LTS (Long Term Support) point releases. It is a special Ubuntu feature that provides an LTS release with hardware support introduced in newer Ubuntu releases. For Ubuntu 12.04 the point releases are .2/.3/.4/.5 and the corresponding Ubuntu releases are 12.10/13.04/13.10/14.04.
The HWE path can be obtained in 2 ways:
- Installing Ubuntu from the media (ISO) for these point releases (where HWE is used by default)
- Manually installing some packages
End-of-life (EOL) for 12.04, 12.04.1, and 12.04.5 HWE is April 2017 but for the other HWE stacks it is roughly when 14.04.1 is released: Aug 8, 2014.
That is, the HWEs for old point releases provide kernels backported from now-EoL Ubuntu releases. So it makes sense that they are to be considered EoL.
Even for a system that does have an old HWE installed, 1204_HWE_EOL is quite explicit about the limited extent to which this renders them unsupported:1
- I am running 12.04.2 HWE. From August 8, 2014 onwards my system will no longer receive package updates?
Not true. Such a system will only stop receiving updates for the kernel and the graphics stack. The rest of the software will continue to get updates.
- So if I am running 12.04.3 (as seen from lsb_release -d) then starting from August 8, 2014 my kernel and graphics stack will no longer receive package updates?
Not true. 12.04.3 is not 12.04.3 HWE. And since HWE (and thus a new kernel series) cannot be introduced through regular package updates it is possible to update a non-HWE system to arrive at a later point release, such as 12.04.3, and still preserve the EOL date of April 2017.
So this is an issue of specific packages being considered end-of-life, and this would only affect HWE-related questions.
1Blockquoted portions of 1204_HWE_EOL by "Contributors to the Ubuntu documentation wiki," reproduced here as permitted by CC-BY-SA 3.0.
As a whole you can assume the server version is on-topic (that includes the kernel and all to the server version related default software).
