diff --git a/README.md b/README.md
index 07784f1..6f31ccc 100644
--- a/README.md
+++ b/README.md
@@ -98,9 +98,13 @@ When devices edit the same file while disconnected, Appa keeps both versions.
 Use `appa folder conflicts <folder>` to find the additional copies, then choose the
 content you want.
 
-Appa keeps 100 local revisions by default. Set `APPA_HISTORY_REVISIONS` to a
+Appa keeps 10 local revisions by default. Set `APPA_HISTORY_REVISIONS` to a
 positive value to change that limit.
 
+Older Appa releases may have left persistent blob tags behind. Use
+`appa doctor --drop-legacy-tags` to remove them; periodic garbage collection
+will later reclaim blobs that are no longer referenced by Appa state.
+
 ## Identity and diagnostics
 
 Each installation has a device identity. Back it up outside synchronized
diff --git a/src/storage.rs b/src/storage.rs
index 95c0ed4..10fe13f 100644
--- a/src/storage.rs
+++ b/src/storage.rs
@@ -47,7 +47,7 @@ pub use manifests::ManifestRevision;
 pub use paths::AppPaths;
 pub use peers::PeerInfo;
 
-const DEFAULT_HISTORY_REVISIONS: usize = 100;
+const DEFAULT_HISTORY_REVISIONS: usize = 10;
 
 pub struct StateStore {
     connection: Connection,
diff --git a/src/storage/tests.rs b/src/storage/tests.rs
index 16b8b1b..90b85d4 100644
--- a/src/storage/tests.rs
+++ b/src/storage/tests.rs
@@ -4,7 +4,8 @@ use tempfile::TempDir;
 use time::{OffsetDateTime, format_description::well_known::Rfc3339};
 
 use super::{
-    AppPaths, FileFingerprint, StateStore, prune_manifest_history, validate_history_revision_limit,
+    AppPaths, DEFAULT_HISTORY_REVISIONS, FileFingerprint, StateStore, prune_manifest_history,
+    validate_history_revision_limit,
 };
 
 #[test]
@@ -365,3 +366,8 @@ fn prunes_manifest_history_to_its_configured_limit() -> anyhow::Result<()> {
 fn rejects_a_zero_history_revision_limit() {
     assert!(validate_history_revision_limit(0).is_err());
 }
+
+#[test]
+fn keeps_ten_revisions_by_default() {
+    assert_eq!(DEFAULT_HISTORY_REVISIONS, 10);
+}