diff --git a/src/groups/calls/moderation.rs b/src/groups/calls/moderation.rs
index ddb63ac..59abd7d 100644
--- a/src/groups/calls/moderation.rs
+++ b/src/groups/calls/moderation.rs
@@ -70,12 +70,13 @@ pub fn escape_message(event: &MessageCreate) -> String {
 }
 
 #[derive(Debug)]
-struct NormalizedMessage {
+pub struct NormalizedMessage {
     /// The normalized message content.
     message: String,
 
-    /// Mappings from original indices to normalized indices, or None if it was removed.
-    mappings: HashMap<(usize, usize), Option<(usize, usize)>>,
+    /// Mappings from normalized start indices to original start indices (indices are grapheme
+    /// indices).
+    mappings: Vec<usize>,
 }
 
 pub fn normalize(message: String) -> NormalizedMessage {
@@ -97,9 +98,7 @@ pub fn normalize(message: String) -> NormalizedMessage {
     .collect();
 
     let mut normalized = String::with_capacity(message.len());
-    let mut mappings = HashMap::new();
-
-    let mut last_i = 0;
+    let mut mappings = Vec::new();
 
     for (i, mut ch) in message
         .grapheme_indices(true)
@@ -111,18 +110,12 @@ pub fn normalize(message: String) -> NormalizedMessage {
 
         let unidecoded = unidecode(&ch);
 
-        let ui_start = normalized.len();
-        let ui_end = ui_start + unidecoded.len();
-
-        if unidecoded.chars().all(|c| c.is_ascii_alphanumeric()) {
-            // If the character is alphanumeric, we can keep it.
-            normalized.push_str(&unidecoded);
-            mappings.insert((last_i, i), Some((ui_start, ui_end)));
-        } else {
-            mappings.insert((last_i, i), None);
+        for char in unidecoded.chars() {
+            if char.is_alphanumeric() {
+                normalized.push(char);
+                mappings.push(i);
+            }
         }
-
-        last_i = i;
     }
 
     NormalizedMessage {
@@ -170,10 +163,20 @@ pub fn analyze_message(message: &str) -> Vec<(Vec<String>, Arc<dyn Rule>)> {
     results
 }
 
-pub fn censor_message(original: &str, normalized: NormalizedMessage, analysis: &[(Vec<String>, Arc<dyn Rule>)]) -> String {
-    let mut censored = String::with_capacity(original.len());
+pub fn censor_message(
+    original: &str,
+    normalized: NormalizedMessage,
+    analysis: &[(Vec<String>, Arc<dyn Rule>)],
+) -> String {
+    let mut censored = original.to_string();
 
-    todo!();
+    for (findings, rule) in analysis {
+        for finding in findings {
+            while let Some(start) = normalized.message.find(finding) {
+                let end = start + finding.len();
+            }
+        }
+    }
 
     censored
 }