diff --git a/message-index/messages/GHC-21926/index.md b/message-index/messages/GHC-21926/index.md
new file mode 100644
index 00000000..cf7b2f5b
--- /dev/null
+++ b/message-index/messages/GHC-21926/index.md
@@ -0,0 +1,11 @@
+---
+title: Version number or non-alphanumeric character in package name
+summary: Package imports may only consist of alphanumeric characters, and must omit the version.
+severity: error
+introduced: 9.6.1
+extension: PackageImports
+---
+
+Version number or non-alphanumeric character in the package. Each of dash-separated components of package name must consist of alphanumeric characters (as defined by `Data.Char.isAlphaNum`), at least one of which is not a digit.
+Note that you will also see this error if the package name consists only of digits.
+The package name in this case refers to the one mentioned in an import when using the `PackageImports` language extension.
diff --git a/message-index/messages/GHC-21926/non-alphanumeric-in-package/after/Non-alphanumeric-in-package.hs b/message-index/messages/GHC-21926/non-alphanumeric-in-package/after/Non-alphanumeric-in-package.hs
new file mode 100644
index 00000000..bd5d4b1e
--- /dev/null
+++ b/message-index/messages/GHC-21926/non-alphanumeric-in-package/after/Non-alphanumeric-in-package.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PackageImports #-}
+
+module NonAlphanumericCharacterNameInPackage where
+
+import "some-existing-package" Package.With.Non.Alphanumeric.Characters
diff --git a/message-index/messages/GHC-21926/non-alphanumeric-in-package/before/Non-alphanumeric-in-package.hs b/message-index/messages/GHC-21926/non-alphanumeric-in-package/before/Non-alphanumeric-in-package.hs
new file mode 100644
index 00000000..852962fe
--- /dev/null
+++ b/message-index/messages/GHC-21926/non-alphanumeric-in-package/before/Non-alphanumeric-in-package.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PackageImports #-}
+
+module NonAlphanumericCharacterNameInPackage where
+
+import "&*$^%!@()" Package.With.Non.Alphanumeric.Characters
diff --git a/message-index/messages/GHC-21926/non-alphanumeric-in-package/index.md b/message-index/messages/GHC-21926/non-alphanumeric-in-package/index.md
new file mode 100644
index 00000000..a944b3d1
--- /dev/null
+++ b/message-index/messages/GHC-21926/non-alphanumeric-in-package/index.md
@@ -0,0 +1,3 @@
+---
+title: Non-alphanumeric characters in the package name
+---
diff --git a/message-index/messages/GHC-21926/version-number-in-package/after/Version-name-in-package.hs b/message-index/messages/GHC-21926/version-number-in-package/after/Version-name-in-package.hs
new file mode 100644
index 00000000..4aa38a03
--- /dev/null
+++ b/message-index/messages/GHC-21926/version-number-in-package/after/Version-name-in-package.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PackageImports #-}
+
+module VersionNameInPackage where
+
+import "some-package" Package.With.Version
diff --git a/message-index/messages/GHC-21926/version-number-in-package/before/Version-name-in-package.hs b/message-index/messages/GHC-21926/version-number-in-package/before/Version-name-in-package.hs
new file mode 100644
index 00000000..3c375a85
--- /dev/null
+++ b/message-index/messages/GHC-21926/version-number-in-package/before/Version-name-in-package.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PackageImports #-}
+
+module VersionNameInPackage where
+
+import "some-package-0.1.2.3" Package.With.Version
diff --git a/message-index/messages/GHC-21926/version-number-in-package/index.md b/message-index/messages/GHC-21926/version-number-in-package/index.md
new file mode 100644
index 00000000..0392b7e8
--- /dev/null
+++ b/message-index/messages/GHC-21926/version-number-in-package/index.md
@@ -0,0 +1,3 @@
+---
+title: Version number in package name
+---