diff --git a/client/src/command/cache.rs b/client/src/command/cache.rs
index afe7671..af01378 100644
--- a/client/src/command/cache.rs
+++ b/client/src/command/cache.rs
@@ -33,6 +33,9 @@ enum Command {
 #[derive(Debug, Clone, Parser)]
 struct Create {
     /// Name of the cache to create.
+    ///
+    /// This can be either `servername:cachename` or `cachename`
+    /// when using the default server.
     cache: CacheRef,
 
     /// Make the cache public.
diff --git a/client/src/command/push.rs b/client/src/command/push.rs
index 98ca04f..087c5ad 100644
--- a/client/src/command/push.rs
+++ b/client/src/command/push.rs
@@ -16,6 +16,9 @@ use attic::nix_store::NixStore;
 #[derive(Debug, Parser)]
 pub struct Push {
     /// The cache to push to.
+    ///
+    /// This can be either `servername:cachename` or `cachename`
+    /// when using the default server.
     cache: CacheRef,
 
     /// The store paths to push.
diff --git a/client/src/command/use.rs b/client/src/command/use.rs
index db651b4..1548072 100644
--- a/client/src/command/use.rs
+++ b/client/src/command/use.rs
@@ -13,6 +13,9 @@ use crate::nix_netrc::NixNetrc;
 #[derive(Debug, Parser)]
 pub struct Use {
     /// The cache to configure.
+    ///
+    /// This can be either `servername:cachename` or `cachename`
+    /// when using the default server.
     cache: CacheRef,
 }
 
diff --git a/client/src/command/watch_store.rs b/client/src/command/watch_store.rs
index e23fdfb..c1af688 100644
--- a/client/src/command/watch_store.rs
+++ b/client/src/command/watch_store.rs
@@ -17,6 +17,9 @@ use attic::nix_store::{NixStore, StorePath};
 #[derive(Debug, Parser)]
 pub struct WatchStore {
     /// The cache to push to.
+    ///
+    /// This can be either `servername:cachename` or `cachename`
+    /// when using the default server.
     cache: CacheRef,
 
     /// Push the new paths only and do not compute closures.