diff --git a/cmd/build.go b/cmd/build.go
index bcc4376035..9ea8920cbd 100644
--- a/cmd/build.go
+++ b/cmd/build.go
@@ -45,6 +45,15 @@ DESCRIPTION
 	When building a function for the first time, either a registry or explicit
 	image name is required.  Subsequent builds will reuse these option values.
 
+	Authentication
+	  When --push is used, the 'build' command interacts with container registries to push the function image.
+	  Authentication can be configured using environment variables:
+	  - FUNC_USERNAME: Username for the registry
+	  - FUNC_PASSWORD: Password for the registry
+	  - FUNC_TOKEN: Token for the registry
+
+	  These variables are used to authenticate with the registry specified by --registry.
+
 EXAMPLES
 
 	o Build a function container using the given registry.
diff --git a/cmd/deploy.go b/cmd/deploy.go
index 98365d2823..84da885145 100644
--- a/cmd/deploy.go
+++ b/cmd/deploy.go
@@ -89,6 +89,15 @@ DESCRIPTION
 	  selectors. Note that the domain specified must be one of those configured
 	  or the flag will be ignored.
 
+	Authentication
+	  The 'deploy' command interacts with container registries to push the function image.
+	  Authentication can be configured using environment variables:
+	  - FUNC_USERNAME: Username for the registry
+	  - FUNC_PASSWORD: Password for the registry
+	  - FUNC_TOKEN: Token for the registry
+
+	  These variables are used to authenticate with the registry specified by --registry.
+
 EXAMPLES
 
 	o Deploy the function
diff --git a/docs/reference/func_build.md b/docs/reference/func_build.md
index 505f2a1709..6eb92df2ec 100644
--- a/docs/reference/func_build.md
+++ b/docs/reference/func_build.md
@@ -28,6 +28,15 @@ DESCRIPTION
 	When building a function for the first time, either a registry or explicit
 	image name is required.  Subsequent builds will reuse these option values.
 
+	Authentication
+	  When --push is used, the 'build' command interacts with container registries to push the function image.
+	  Authentication can be configured using environment variables:
+	  - FUNC_USERNAME: Username for the registry
+	  - FUNC_PASSWORD: Password for the registry
+	  - FUNC_TOKEN: Token for the registry
+
+	  These variables are used to authenticate with the registry specified by --registry.
+
 EXAMPLES
 
 	o Build a function container using the given registry.
diff --git a/docs/reference/func_deploy.md b/docs/reference/func_deploy.md
index 2769a21fd8..06a6faca30 100644
--- a/docs/reference/func_deploy.md
+++ b/docs/reference/func_deploy.md
@@ -66,6 +66,15 @@ DESCRIPTION
 	  selectors. Note that the domain specified must be one of those configured
 	  or the flag will be ignored.
 
+	Authentication
+	  The 'deploy' command interacts with container registries to push the function image.
+	  Authentication can be configured using environment variables:
+	  - FUNC_USERNAME: Username for the registry
+	  - FUNC_PASSWORD: Password for the registry
+	  - FUNC_TOKEN: Token for the registry
+
+	  These variables are used to authenticate with the registry specified by --registry.
+
 EXAMPLES
 
 	o Deploy the function