Update supported platforms documentation (#6540)

Author: lbussell

documentation/supported-platforms.md

@@ -9,19 +9,27 @@ This document describes the platforms (OS and architectures) supported by the of
 - Images for new OS versions are typically released within one month of the new OS release, with a goal to release same-day when possible.
 - New OS versions are available in [`dotnet/nightly` repositories](https://github.com/dotnet/dotnet-docker/blob/nightly/README.md) first, and are added to the officially supported repos afterwards.
 - All new OS releases will be accompanied by an [announcement](https://github.com/dotnet/dotnet-docker/discussions/categories/announcements).
+- Unless otherwise specified (see Alpine Linux below), we stop publishing updates to images when the .NET version in the image reaches [end of support](https://dotnet.microsoft.com/platform/support/policy/dotnet-core) or when the OS base image stops receiving updates, whichever happens first.
 
 These policies are specific to .NET container images. For more information on overall .NET OS support, see [.NET OS Support Tracking](https://github.com/dotnet/core/issues/9638).
 
 ### Linux
 
-Each distribution (distro) has a unique approach to releasing, schedule, and end-of life (EOL). This prohibits the definition of a one-size-fits-all policy. Instead, a policy is defined for each supported distro.
-
-- Alpine — support latest and retain support for the previous version one quarter (3 months) after a new version is released.
-- Azure Linux — support the latest *stable* version at the time a `major.minor` version of .NET is released. As new *stable* versions are released, support is added to the latest .NET version and latest LTS (if they differ).
-- Debian — support the latest *stable* version at the time a `major.minor` version of .NET is released. As new *stable* versions are released, support is added to the latest .NET version and latest LTS (if they differ) via an [OS-specific tag](supported-tags.md#os-tags-and-base-image-updates).
-- Ubuntu — support the latest *LTS* version at the time a `major.minor` version of .NET is released. As new *LTS* versions are released, support is added to the latest .NET version and latest LTS (if they differ).
-
-Pre-release versions of the supported distros will be made available within the [nightly repositories](https://github.com/dotnet/dotnet-docker/blob/nightly/README.md) based on the availability of pre-release OS base images.
+Since Linux distributions ("distros") each have unique release and support policies, a one-size-fits-all policy doesn't make sense.
+Instead, we have separate policies for each distro.
+We publish .NET container images for the following versions of each Linux distro:
+
+- Alpine Linux
+  - .NET images will be published for the latest Alpine Linux version.
+  - When new Alpine versions are released, new images will be added for all in-support .NET versions.
+  - .NET images for the previous version of Alpine will published for 3 months after the new version is released.
+- Azure Linux and Ubuntu LTS
+  - .NET images will be published images for the latest OS version at the time a new major/minor version of .NET is released.
+  - When new OS versions are released, new images will be added to the latest .NET version and latest LTS .NET version (if they differ).
+- Debian
+  - Existing .NET Debian images will continue to receive base image updates, but new .NET images will not be added for future Debian versions.
+
+Pre-release versions of the above distros will be published in the [nightly repositories](https://github.com/dotnet/dotnet-docker/blob/nightly/README.md), pending the availability of pre-release base images.
 
 #### FedRAMP Compliance
 

documentation/supported-tags.md

@@ -49,7 +49,8 @@ These tags reference images for [multiple platforms](https://docs.docker.com/bui
 
 They include:
 
-- Debian, unless specified (like `8.0-alpine`).
+- For .NET 10, multi-platform tags refer to Ubuntu unless otherwise specified (like `8.0-alpine`).
+- For .NET versions prior to 10, multi-platform tags refer to Debian unless otherwise specified.
 - All [supported architectures](supported-platforms.md#architectures).
 
 > [!WARNING]
@@ -235,7 +236,7 @@ For Windows, `amd64` is the only architecture supported and is excluded from the
 
 Each tag will be supported for the lifetime of the .NET and OS version referenced by the tag, unless further restricted according to [platform support policy](supported-platforms.md).
 
-When a .NET version or an OS version reaches End-of-Life (EOL), its tags will no longer be supported.
+When a .NET version or an OS version reaches [end of support](https://dotnet.microsoft.com/platform/support/policy/dotnet-core) (sometimes referred to as end-of-life or EOL), its tags will no longer be supported.
 Unsupported tags and images can still be pulled, but they will no longer receive updates for any reason.
 
 See ["Is your image built from a supported .NET tag?"](vulnerability-reporting.md#c-is-your-image-built-from-a-supported-net-tag) for details on how to tell if a specific tag is supported.