diff --git a/quickpeep_raker/src/raking/task.rs b/quickpeep_raker/src/raking/task.rs
index ce4beb2..c447864 100644
--- a/quickpeep_raker/src/raking/task.rs
+++ b/quickpeep_raker/src/raking/task.rs
@@ -4,7 +4,7 @@ use crate::raking::{
     get_robots_txt_for, robots_txt_url_for, PermanentFailure, PermanentFailureReason, RakeOutcome,
     Raker, RedirectReason, RobotsTxt, TemporaryFailure, TemporaryFailureReason,
 };
-use crate::storage::records::UrlVisitedRecord;
+use crate::storage::records::{AllowedDomainRecord, UrlVisitedRecord};
 use crate::storage::{RakerStore, RandomActiveDomainAcquisition};
 use anyhow::{anyhow, ensure, Context};
 use chrono::Utc;
@@ -16,7 +16,7 @@ use quickpeep_structs::rake_entries::{
 };
 use quickpeep_utils::dates::date_to_quickpeep_days;
 use reqwest::{Client, Url};
-use std::borrow::Cow;
+use std::borrow::{Borrow, Cow};
 use std::collections::HashSet;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex as StdMutex, RwLock};
@@ -469,7 +469,42 @@ impl EventProcessor<'_> {
 
                 // track all the referred-to URLs!
                 for reference in refs.references {
-                    txn.enqueue_url(&reference.target, reference.last_mod, reference.kind.into())?;
+                    let ref_url = Url::parse(&reference.target)?;
+                    let domain = get_reduced_domain(&ref_url)?;
+                    let allowed = match txn.get_allowed_domain_record(domain.borrow())? {
+                        None => false,
+                        Some(AllowedDomainRecord {
+                            restricted_prefixes,
+                        }) => {
+                            if restricted_prefixes.is_empty() {
+                                true
+                            } else {
+                                let mut allowed = false;
+                                for prefix in restricted_prefixes.iter() {
+                                    if ref_url.path().starts_with(prefix) {
+                                        allowed = true;
+                                        break;
+                                    }
+                                    if prefix.as_str() > ref_url.path() {
+                                        // e.g. /dog > /cat/xyz
+                                        // This means we've missed all chances to see our prefix,
+                                        // so we break here (efficiency).
+                                        break;
+                                    }
+                                }
+                                allowed
+                            }
+                        }
+                    };
+                    if allowed {
+                        txn.enqueue_url(
+                            &reference.target,
+                            reference.last_mod,
+                            reference.kind.into(),
+                        )?;
+                    } else {
+                        txn.put_url_on_hold(&reference.target, reference.kind.into())?;
+                    }
                 }
 
                 txn.commit()?;
diff --git a/quickpeep_raker/src/storage.rs b/quickpeep_raker/src/storage.rs
index e8d1fc7..1b85671 100644
--- a/quickpeep_raker/src/storage.rs
+++ b/quickpeep_raker/src/storage.rs
@@ -3,8 +3,8 @@ use crate::raking::{RakeIntent, TemporaryFailure};
 use crate::storage::mdbx_helper_types::{MdbxBare, MdbxString, MdbxU32, MdbxU64};
 use crate::storage::migrations::{MIGRATION_KEY, MIGRATION_VERSION};
 use crate::storage::records::{
-    ActiveDomainRecord, AllowedDomainRecord, BackingOffDomainRecord, QueueUrlRecord,
-    UrlVisitedRecord,
+    ActiveDomainRecord, AllowedDomainRecord, BackingOffDomainRecord, OnHoldUrlRecord,
+    QueueUrlRecord, UrlVisitedRecord,
 };
 use anyhow::{anyhow, bail, ensure, Context};
 use libmdbx::{
@@ -42,7 +42,7 @@ pub struct Databases<'env> {
     pub visited_urls: Database<'env>,
     /// Domain → AllowedDomainRecord
     pub allowed_domains: Database<'env>,
-    /// Domain \n URL → Number of refs (INT VALUE)
+    /// Domain \n URL → OnHoldUrlRecord Number of refs (INT VALUE)
     pub urls_on_hold: Database<'env>,
 }
 
@@ -58,6 +58,8 @@ impl<'env> Databases<'env> {
             ),
             ("backing_off_domains", &self.backing_off_domains),
             ("visited_urls", &self.visited_urls),
+            ("allowed_domains", &self.allowed_domains),
+            ("urls_on_hold", &self.urls_on_hold),
         ]
         .into_iter()
     }
@@ -439,6 +441,46 @@ impl<'a> RakerTxn<'a, RW> {
         Ok(true)
     }
 
+    /// Enqueues a URL to the 'on hold' queue.
+    ///
+    /// Returns: true if it was enqueued, false if nothing changed.
+    pub fn put_url_on_hold(&self, url_str: &str, intent: RakeIntent) -> anyhow::Result<bool> {
+        let urls_on_hold = &self.mdbx.borrow_dbs().urls_on_hold;
+
+        let url = Url::parse(url_str)?;
+        let url_domain = get_reduced_domain(&url)?;
+
+        let queue_key = format!("{}\n{}", url_domain, url);
+
+        let (record, is_new) = if let Some(mut record) = self
+            .mdbx_txn
+            .get::<MdbxBare<OnHoldUrlRecord>>(urls_on_hold, queue_key.as_bytes())?
+        {
+            // Already in the queue. Nothing to do here, except bump up the refs count.
+            record.0.refs = record.0.refs.saturating_add(1);
+
+            (record, false)
+        } else {
+            (
+                MdbxBare(OnHoldUrlRecord {
+                    refs: 1,
+                    queue_record: QueueUrlRecord { intent },
+                }),
+                true,
+            )
+        };
+
+        // Add the entry to the queue
+        self.mdbx_txn.put(
+            urls_on_hold,
+            queue_key.as_bytes(),
+            &record.as_bytes(),
+            WriteFlags::empty(),
+        )?;
+
+        Ok(is_new)
+    }
+
     pub fn put_allowed_domain_record(
         &self,
         domain: &str,
diff --git a/quickpeep_raker/src/storage/records.rs b/quickpeep_raker/src/storage/records.rs
index 2cafdbe..91c9976 100644
--- a/quickpeep_raker/src/storage/records.rs
+++ b/quickpeep_raker/src/storage/records.rs
@@ -23,6 +23,15 @@ pub struct QueueUrlRecord {
     pub intent: RakeIntent, // TODO CONSIDER
 }
 
+#[derive(Clone, Debug, Deserialize, Serialize)]
+pub struct OnHoldUrlRecord {
+    /// Record that should be emitted once this is released.
+    pub queue_record: QueueUrlRecord,
+
+    /// Number of times this URL has been 'enqueued'; capped at 255.
+    pub refs: u8,
+}
+
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct BackingOffDomainRecord {
     /// The URL that caused the backoff.