diff --git a/data-model/src/lengthy_entry.rs b/data-model/src/lengthy_entry.rs
index 1941062..06fa898 100644
--- a/data-model/src/lengthy_entry.rs
+++ b/data-model/src/lengthy_entry.rs
@@ -3,6 +3,7 @@ use crate::{AuthorisationToken, AuthorisedEntry, Entry, NamespaceId, PayloadDige
 /// An [`Entry`] together with information about how much of its payload a given [`Store`] holds.
 ///
 /// [Definition](https://willowprotocol.org/specs/3d-range-based-set-reconciliation/index.html#LengthyEntry)
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct LengthyEntry<const MCL: usize, const MCC: usize, const MPL: usize, N, S, PD>
 where
     N: NamespaceId,
@@ -56,6 +57,7 @@ where
 }
 
 /// An [`AuthorisedEntry`] together with information about how much of its payload a given [`Store`] holds.
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct LengthyAuthorisedEntry<
     const MCL: usize,
     const MCC: usize,
diff --git a/data-model/src/store.rs b/data-model/src/store.rs
index aae9ea1..ae70f00 100644
--- a/data-model/src/store.rs
+++ b/data-model/src/store.rs
@@ -1,4 +1,8 @@
-use std::future::Future;
+use std::{
+    error::Error,
+    fmt::{Debug, Display},
+    future::Future,
+};
 
 use ufotofu::{local_nb::Producer, nb::BulkProducer};
 
@@ -10,6 +14,7 @@ use crate::{
 };
 
 /// Returned when an entry could be ingested into a [`Store`].
+#[derive(Debug, Clone)]
 pub enum EntryIngestionSuccess<
     const MCL: usize,
     const MCC: usize,
@@ -31,6 +36,7 @@ pub enum EntryIngestionSuccess<
 }
 
 /// Returned when an entry cannot be ingested into a [`Store`].
+#[derive(Debug, Clone)]
 pub enum EntryIngestionError<
     const MCL: usize,
     const MCC: usize,
@@ -39,7 +45,7 @@ pub enum EntryIngestionError<
     S: SubspaceId,
     PD: PayloadDigest,
     AT,
-    OE,
+    OE: Display + Error,
 > {
     /// The entry belonged to another namespace.
     WrongNamespace(AuthorisedEntry<MCL, MCC, MPL, N, S, PD, AT>),
@@ -49,6 +55,43 @@ pub enum EntryIngestionError<
     OperationsError(OE),
 }
 
+impl<
+        const MCL: usize,
+        const MCC: usize,
+        const MPL: usize,
+        N: NamespaceId,
+        S: SubspaceId,
+        PD: PayloadDigest,
+        AT,
+        OE: Display + Error,
+    > Display for EntryIngestionError<MCL, MCC, MPL, N, S, PD, AT, OE>
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            EntryIngestionError::WrongNamespace(_) => {
+                write!(f, "Tried to ingest an entry from a different namespace.")
+            }
+            EntryIngestionError::PruningPrevented => {
+                write!(f, "Entry ingestion would have triggered undesired pruning.")
+            }
+            EntryIngestionError::OperationsError(err) => Display::fmt(err, f),
+        }
+    }
+}
+
+impl<
+        const MCL: usize,
+        const MCC: usize,
+        const MPL: usize,
+        N: NamespaceId + Debug,
+        S: SubspaceId + Debug,
+        PD: PayloadDigest + Debug,
+        AT: Debug,
+        OE: Display + Error,
+    > Error for EntryIngestionError<MCL, MCC, MPL, N, S, PD, AT, OE>
+{
+}
+
 /// A tuple of an [`AuthorisedEntry`] and how a [`Store`] responded to its ingestion.
 pub type BulkIngestionResult<
     const MCL: usize,
@@ -68,6 +111,7 @@ pub type BulkIngestionResult<
 );
 
 /// Returned when a bulk ingestion failed due to a consumer error.
+#[derive(Debug, Clone)]
 pub struct BulkIngestionError<
     const MCL: usize,
     const MCC: usize,
@@ -76,14 +120,50 @@ pub struct BulkIngestionError<
     S: SubspaceId,
     PD: PayloadDigest,
     AT: AuthorisationToken<MCL, MCC, MPL, N, S, PD>,
-    OE,
+    OE: Error,
     IngestionError,
 > {
     pub ingested: Vec<BulkIngestionResult<MCL, MCC, MPL, N, S, PD, AT, OE>>,
     pub error: IngestionError,
 }
 
+impl<
+        const MCL: usize,
+        const MCC: usize,
+        const MPL: usize,
+        N: NamespaceId,
+        S: SubspaceId,
+        PD: PayloadDigest,
+        AT: AuthorisationToken<MCL, MCC, MPL, N, S, PD>,
+        OE: Display + Error,
+        IngestionError: Error,
+    > std::fmt::Display for BulkIngestionError<MCL, MCC, MPL, N, S, PD, AT, OE, IngestionError>
+{
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "An error stopped bulk ingestion after successfully ingesting {:?} entries",
+            self.ingested.len()
+        )
+    }
+}
+
+impl<
+        const MCL: usize,
+        const MCC: usize,
+        const MPL: usize,
+        N: NamespaceId + Debug,
+        S: SubspaceId + Debug,
+        PD: PayloadDigest + Debug,
+        AT: AuthorisationToken<MCL, MCC, MPL, N, S, PD> + Debug,
+        OE: Display + Error,
+        IngestionError: Error,
+    > Error for BulkIngestionError<MCL, MCC, MPL, N, S, PD, AT, OE, IngestionError>
+{
+}
+
 /// Return when a payload is successfully appended to the [`Store`].
+#[derive(Debug, Clone)]
 pub enum PayloadAppendSuccess<const MCL: usize, const MCC: usize, const MPL: usize, N, S, PD>
 where
     N: NamespaceId,
@@ -97,6 +177,7 @@ where
 }
 
 /// Returned when a payload fails to be appended into the [`Store`].
+#[derive(Debug, Clone)]
 pub enum PayloadAppendError<OE> {
     /// None of the entries in the store reference this payload.
     NotEntryReference,
@@ -110,10 +191,44 @@ pub enum PayloadAppendError<OE> {
     OperationError(OE),
 }
 
+impl<OE: Display + Error> Display for PayloadAppendError<OE> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            PayloadAppendError::NotEntryReference => write!(
+                f,
+                "None of the entries in the soter reference this payload."
+            ),
+            PayloadAppendError::AlreadyHaveIt => {
+                write!(f, "The payload is already held in storage.")
+            }
+            PayloadAppendError::TooManyBytes => write!(
+                f,
+                "The payload source produced more bytes than were expected for this payload."
+            ),
+            PayloadAppendError::DigestMismatch => {
+                write!(f, "The complete payload's digest is not what was expected.")
+            }
+            PayloadAppendError::OperationError(err) => std::fmt::Display::fmt(err, f),
+        }
+    }
+}
+
+impl<OE: Display + Error> Error for PayloadAppendError<OE> {}
+
 /// Returned when no entry was found for some criteria.
+#[derive(Debug, Clone)]
 pub struct NoSuchEntryError;
 
+impl Display for NoSuchEntryError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "No entry was found for the given criteria.")
+    }
+}
+
+impl Error for NoSuchEntryError {}
+
 /// The order by which entries should be returned for a given query.
+#[derive(Debug, Clone)]
 pub enum QueryOrder {
     /// Ordered by subspace, then path, then timestamp.
     Subspace,
@@ -126,6 +241,7 @@ pub enum QueryOrder {
 }
 
 /// Describes an [`AuthorisedEntry`] which was pruned and the [`AuthorisedEntry`] which triggered the pruning.
+#[derive(Debug, Clone)]
 pub struct PruneEvent<const MCL: usize, const MCC: usize, const MPL: usize, N, S, PD, AT>
 where
     N: NamespaceId,
@@ -141,6 +257,7 @@ where
 
 /// An event which took place within a [`Store`].
 /// Each event includes a *progress ID* which can be used to *resume* a subscription at any point in the future.
+#[derive(Debug, Clone)]
 pub enum StoreEvent<const MCL: usize, const MCC: usize, const MPL: usize, N, S, PD, AT>
 where
     N: NamespaceId,
@@ -149,7 +266,11 @@ where
     AT: AuthorisationToken<MCL, MCC, MPL, N, S, PD>,
 {
     /// A new entry was ingested.
-    Ingested(u64, AuthorisedEntry<MCL, MCC, MPL, N, S, PD, AT>),
+    Ingested(
+        u64,
+        AuthorisedEntry<MCL, MCC, MPL, N, S, PD, AT>,
+        EntryOrigin,
+    ),
     /// An existing entry received a portion of its corresponding payload.
     Appended(u64, LengthyAuthorisedEntry<MCL, MCC, MPL, N, S, PD, AT>),
     /// An entry was forgotten.
@@ -161,10 +282,23 @@ where
 }
 
 /// Returned when the store chooses to not resume a subscription.
+#[derive(Debug, Clone)]
 pub struct ResumptionFailedError(pub u64);
 
+impl Display for ResumptionFailedError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "The subscription with ID {:?} could not be resumed.",
+            self.0
+        )
+    }
+}
+
+impl Error for ResumptionFailedError {}
+
 /// Describes which entries to ignore during a query.
-#[derive(Default)]
+#[derive(Default, Clone)]
 pub struct QueryIgnoreParams {
     /// Omit entries with locally incomplete corresponding payloads.
     pub ignore_incomplete_payloads: bool,
@@ -183,11 +317,41 @@ impl QueryIgnoreParams {
 }
 
 /// Returned when a payload could not be forgotten.
+#[derive(Debug, Clone)]
 pub enum ForgetPayloadError {
     NoSuchEntry,
     ReferredToByOtherEntries,
 }
 
+impl Display for ForgetPayloadError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ForgetPayloadError::NoSuchEntry => {
+                write!(
+                    f,
+                    "No entry for the given criteria could be found in this store."
+                )
+            }
+            ForgetPayloadError::ReferredToByOtherEntries => write!(
+                f,
+                "The payload could not be forgotten because it is referred to by other entries."
+            ),
+        }
+    }
+}
+
+impl Error for ForgetPayloadError {}
+
+/// The origin of an entry ingestion event.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum EntryOrigin {
+    /// The entry was probably created on this machine.
+    Local,
+    /// The entry was sourced from another source with an ID assigned by us.
+    /// This is useful if you want to suppress the forwarding of entries to the peers from which the entry was originally sourced.
+    Remote(u64),
+}
+
 /// A [`Store`] is a set of [`AuthorisedEntry`] belonging to a single namespace, and a  (possibly partial) corresponding set of payloads.
 pub trait Store<const MCL: usize, const MCC: usize, const MPL: usize, N, S, PD, AT>
 where
@@ -196,9 +360,9 @@ where
     PD: PayloadDigest,
     AT: AuthorisationToken<MCL, MCC, MPL, N, S, PD>,
 {
-    type FlushError;
-    type BulkIngestionError;
-    type OperationsError;
+    type FlushError: Display + Error;
+    type BulkIngestionError: Display + Error;
+    type OperationsError: Display + Error;
 
     /// The [namespace](https://willowprotocol.org/specs/data-model/index.html#namespace) which all of this store's [`AuthorisedEntry`] belong to.
     fn namespace_id() -> N;
@@ -363,14 +527,14 @@ where
     /// Subscribe to events concerning entries [included](https://willowprotocol.org/specs/grouping-entries/index.html#area_include) by an [`AreaOfInterest`], returning a producer of `StoreEvent`s which occurred since the moment of calling this function.
     fn subscribe_area(
         &self,
-        area: &AreaOfInterest<MCL, MCC, MPL, S>,
+        area: &Area<MCL, MCC, MPL, S>,
         ignore: Option<QueryIgnoreParams>,
     ) -> impl Producer<Item = StoreEvent<MCL, MCC, MPL, N, S, PD, AT>>;
 
     /// Attempt to resume a subscription using a *progress ID* obtained from a previous subscription, or return an error if this store implementation is unable to resume the subscription.
     fn resume_subscription(
         progress_id: u64,
-        area: AreaOfInterest<MCL, MCC, MPL, S>,
+        area: &Area<MCL, MCC, MPL, S>,
         ignore: Option<QueryIgnoreParams>,
     ) -> Result<impl Producer<Item = StoreEvent<MCL, MCC, MPL, N, S, PD, AT>>, ResumptionFailedError>;
 }