diff --git a/docs/source/guides/admin-guides/references/man1/imgexport.1.rst b/docs/source/guides/admin-guides/references/man1/imgexport.1.rst
index 24a989a61..94fe7f237 100644
--- a/docs/source/guides/admin-guides/references/man1/imgexport.1.rst
+++ b/docs/source/guides/admin-guides/references/man1/imgexport.1.rst
@@ -41,7 +41,7 @@ For stateful:
 For stateless:
   kernel
   initrd.gz
-  rootimg.gz
+  rootimg.cpio.xz or rootimg.cpio.gz or rootimg.tar.xz or rootimg.tar.gz or rootimg.gz(for backward-compatibility)
   x.pkglist
   x.otherpkgs.pkglist
   x.synclist
diff --git a/docs/source/guides/admin-guides/references/man1/imgimport.1.rst b/docs/source/guides/admin-guides/references/man1/imgimport.1.rst
index a0ef47ede..49384e7eb 100644
--- a/docs/source/guides/admin-guides/references/man1/imgimport.1.rst
+++ b/docs/source/guides/admin-guides/references/man1/imgimport.1.rst
@@ -41,7 +41,7 @@ For stateful, the following files will be copied to the appropriate directories.
 For stateless, the following files will be copied to the appropriate directories.
   kernel
   initrd.gz
-  rootimg.gz
+  rootimg.cpio.xz or rootimg.cpio.gz or rootimg.tar.xz or rootimg.tar.gz or rootimg.gz(for backward-compatibility)
   x.pkglist
   x.otherpkgs.pkglist
   x.synclist
diff --git a/xCAT-client/pods/man1/imgexport.1.pod b/xCAT-client/pods/man1/imgexport.1.pod
index 9b45f4638..d3a1c2648 100644
--- a/xCAT-client/pods/man1/imgexport.1.pod
+++ b/xCAT-client/pods/man1/imgexport.1.pod
@@ -23,7 +23,7 @@ For stateful:
 For stateless:
   kernel
   initrd.gz
-  rootimg.gz
+  rootimg.cpio.xz or rootimg.cpio.gz or rootimg.tar.xz or rootimg.tar.gz or rootimg.gz(for backward-compatibility)
   x.pkglist
   x.otherpkgs.pkglist
   x.synclist
diff --git a/xCAT-client/pods/man1/imgimport.1.pod b/xCAT-client/pods/man1/imgimport.1.pod
index 0d89f089e..b674ea048 100644
--- a/xCAT-client/pods/man1/imgimport.1.pod
+++ b/xCAT-client/pods/man1/imgimport.1.pod
@@ -22,7 +22,7 @@ For stateful, the following files will be copied to the appropriate directories.
 For stateless, the following files will be copied to the appropriate directories.
   kernel
   initrd.gz
-  rootimg.gz
+  rootimg.cpio.xz or rootimg.cpio.gz or rootimg.tar.xz or rootimg.tar.gz or rootimg.gz(for backward-compatibility)
   x.pkglist
   x.otherpkgs.pkglist
   x.synclist