diff --git a/Dockerfile b/Dockerfile
index f5213cbf1..1b35d5157 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,10 @@
 # syntax=docker/dockerfile:1
 
 ARG BASE_VARIANT=alpine
+
+# ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image.
+# It must be a supported tag in the docker.io/library/alpine image repository
+# that's also available as alpine image variant for the Golang version used.
 ARG ALPINE_VERSION=3.21
 ARG BASE_DEBIAN_DISTRO=bookworm
 
diff --git a/dockerfiles/Dockerfile.authors b/dockerfiles/Dockerfile.authors
index 35d792831..e2a25e841 100644
--- a/dockerfiles/Dockerfile.authors
+++ b/dockerfiles/Dockerfile.authors
@@ -1,5 +1,7 @@
 # syntax=docker/dockerfile:1
 
+# ALPINE_VERSION sets the version of the alpine base image to use.
+# It must be a supported tag in the docker.io/library/alpine image repository.
 ARG ALPINE_VERSION=3.21
 
 FROM alpine:${ALPINE_VERSION} AS gen
diff --git a/dockerfiles/Dockerfile.dev b/dockerfiles/Dockerfile.dev
index 4067f16de..4b481f256 100644
--- a/dockerfiles/Dockerfile.dev
+++ b/dockerfiles/Dockerfile.dev
@@ -1,6 +1,10 @@
 # syntax=docker/dockerfile:1
 
 ARG GO_VERSION=1.24.5
+
+# ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image.
+# It must be a supported tag in the docker.io/library/alpine image repository
+# that's also available as alpine image variant for the Golang version used.
 ARG ALPINE_VERSION=3.21
 
 # BUILDX_VERSION sets the version of buildx to install in the dev container.
diff --git a/dockerfiles/Dockerfile.lint b/dockerfiles/Dockerfile.lint
index 1f1095132..345943c2e 100644
--- a/dockerfiles/Dockerfile.lint
+++ b/dockerfiles/Dockerfile.lint
@@ -1,6 +1,10 @@
 # syntax=docker/dockerfile:1
 
 ARG GO_VERSION=1.24.5
+
+# ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image.
+# It must be a supported tag in the docker.io/library/alpine image repository
+# that's also available as alpine image variant for the Golang version used.
 ARG ALPINE_VERSION=3.21
 ARG GOLANGCI_LINT_VERSION=v2.1.5
 
diff --git a/dockerfiles/Dockerfile.vendor b/dockerfiles/Dockerfile.vendor
index 4b9cea56b..e70a59217 100644
--- a/dockerfiles/Dockerfile.vendor
+++ b/dockerfiles/Dockerfile.vendor
@@ -1,6 +1,10 @@
 # syntax=docker/dockerfile:1
 
 ARG GO_VERSION=1.24.5
+
+# ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image.
+# It must be a supported tag in the docker.io/library/alpine image repository
+# that's also available as alpine image variant for the Golang version used.
 ARG ALPINE_VERSION=3.21
 ARG MODOUTDATED_VERSION=v0.8.0