diff --git a/src/IIIF/IIIF.Tests/Presentation/HtmlSanitiserTests.cs b/src/IIIF/IIIF.Tests/Presentation/HtmlSanitiserTests.cs
index 37b3d23..f9049f7 100644
--- a/src/IIIF/IIIF.Tests/Presentation/HtmlSanitiserTests.cs
+++ b/src/IIIF/IIIF.Tests/Presentation/HtmlSanitiserTests.cs
@@ -11,6 +11,19 @@ public class HtmlSanitiserTests
     public void SanitiseHtml_ReturnsGivenString_IfNullOrEmpty(string val)
         => val.SanitiseHtml().Should().Be(val);
 
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void SanitiseHtml_ReturnsEmptyString_IfGivenInvalidHtml(bool ignoreNonHtml)
+    {
+        const string input = "<div>invalid html</div>";
+        const string expected = "";
+
+        var actual = input.SanitiseHtml(ignoreNonHtml);
+
+        actual.Should().Be(expected);
+    }
+    
     [Fact]
     public void SanitiseHtml_Trims_Whitespace_FromBeginningAndEnd_IfIgnoreNonHtmlFalse()
     {
diff --git a/src/IIIF/IIIF.Tests/Presentation/V3/LabelValuePairXTests.cs b/src/IIIF/IIIF.Tests/Presentation/V3/LabelValuePairXTests.cs
new file mode 100644
index 0000000..41bea6c
--- /dev/null
+++ b/src/IIIF/IIIF.Tests/Presentation/V3/LabelValuePairXTests.cs
@@ -0,0 +1,64 @@
+using System.Collections.Generic;
+using IIIF.Presentation.V3;
+using IIIF.Presentation.V3.Strings;
+
+namespace IIIF.Tests.Presentation.V3;
+
+public class LabelValuePairXTests
+{
+    [Fact]
+    public void TryGetValue_False_NullList()
+    {
+        List<LabelValuePair> metadata = null;
+
+        var result = metadata.TryGetValue("en", "bar", out var languageMap);
+
+        result.Should().BeFalse();
+        languageMap.Should().BeNull();
+    }
+    
+    [Fact]
+    public void TryGetValue_False_EmptyList()
+    {
+        var metadata = new List<LabelValuePair>();
+
+        var result = metadata.TryGetValue("en", "bar", out var languageMap);
+
+        result.Should().BeFalse();
+        languageMap.Should().BeNull();
+    }
+    
+    [Fact]
+    public void TryGetValue_True_ReturnsCorrect_IfFound()
+    {
+        var metadata = new List<LabelValuePair> { new("en", "foo", "bar", "baz") };
+        var expected = new LanguageMap("en", new[] { "bar", "baz" });
+
+        var result = metadata.TryGetValue("en", "foo", out var languageMap);
+
+        result.Should().BeTrue();
+        languageMap.Should().BeEquivalentTo(expected);
+    }
+    
+    [Fact]
+    public void TryGetValue_False_IfNotFoundForLanguage()
+    {
+        var metadata = new List<LabelValuePair> { new("en", "foo", "bar", "baz") };
+
+        var result = metadata.TryGetValue("en", "bar", out var languageMap);
+
+        result.Should().BeFalse();
+        languageMap.Should().BeNull();
+    }
+    
+    [Fact]
+    public void TryGetValue_False_IfLabelForDifferentLanguage()
+    {
+        var metadata = new List<LabelValuePair> { new("en", "foo", "bar", "baz") };
+
+        var result = metadata.TryGetValue("fr", "bar", out var languageMap);
+
+        result.Should().BeFalse();
+        languageMap.Should().BeNull();
+    }
+}
\ No newline at end of file
diff --git a/src/IIIF/IIIF/Presentation/HtmlSanitiser.cs b/src/IIIF/IIIF/Presentation/HtmlSanitiser.cs
index a4ab7b6..0470b0b 100644
--- a/src/IIIF/IIIF/Presentation/HtmlSanitiser.cs
+++ b/src/IIIF/IIIF/Presentation/HtmlSanitiser.cs
@@ -72,6 +72,7 @@ public static string SanitiseHtml(this string propertyValue, bool ignoreNonHtml
 
         var workingString = Sanitizer.Sanitize(propertyValue.Trim());
 
+        if (string.IsNullOrEmpty(workingString)) return workingString;
         if (IsHtmlString(workingString)) return workingString;
         
         if (!HtmlSanitizerOptions.AllowedTags.Contains(nonHtmlWrappingTag))
@@ -85,5 +86,6 @@ public static string SanitiseHtml(this string propertyValue, bool ignoreNonHtml
         return Sanitizer.Sanitize(workingString);
     }
 
-    private static bool IsHtmlString(string candidate) => candidate[0] == '<' && candidate[^1] == '>';
+    private static bool IsHtmlString(string candidate) 
+        => candidate[0] == '<' && candidate[^1] == '>';
 }
\ No newline at end of file
diff --git a/src/IIIF/IIIF/Presentation/V3/LabelValuePairX.cs b/src/IIIF/IIIF/Presentation/V3/LabelValuePairX.cs
new file mode 100644
index 0000000..788bbd2
--- /dev/null
+++ b/src/IIIF/IIIF/Presentation/V3/LabelValuePairX.cs
@@ -0,0 +1,39 @@
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+using IIIF.Presentation.V3.Strings;
+using IIIF.Utils;
+
+namespace IIIF.Presentation.V3;
+
+public static class LabelValuePairX
+{
+    /// <summary>
+    /// Try get values associated with specified language and label.
+    /// </summary>
+    /// <param name="labelValuePairs">Collection of <see cref="labelValuePairs"/> to search</param>
+    /// <param name="language">Language to get values for</param>
+    /// <param name="label">Label to get values for</param>
+    /// <param name="languageMap">Found <see cref="LanguageMap"/></param>
+    /// <returns>true if matching value found, else false</returns>
+    public static bool TryGetValue(
+        this List<LabelValuePair>? labelValuePairs, 
+        string language, 
+        string label,
+        [NotNullWhen(true)] out LanguageMap? languageMap)
+    {
+        languageMap = null;
+        if (labelValuePairs.IsNullOrEmpty()) return false;
+
+        foreach (var langValues in labelValuePairs.Where(lvp => lvp.Label.ContainsKey(language)))
+        {
+            if (langValues.Label.Any(l => l.Value.Contains(label)))
+            {
+                languageMap = langValues.Value;
+                return true;
+            }
+        }
+
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/src/IIIF/IIIF/Presentation/V3/ResourceBase.cs b/src/IIIF/IIIF/Presentation/V3/ResourceBase.cs
index 801f164..725acc1 100644
--- a/src/IIIF/IIIF/Presentation/V3/ResourceBase.cs
+++ b/src/IIIF/IIIF/Presentation/V3/ResourceBase.cs
@@ -119,4 +119,4 @@ public abstract class ResourceBase : JsonLdBase, IResource
     /// </summary>
     [JsonProperty(Order = 1000)]
     public List<ResourceBase>? PartOf { get; set; }
-}
\ No newline at end of file
+}
diff --git a/src/IIIF/IIIF/Presentation/V3/Strings/LabelValuePair.cs b/src/IIIF/IIIF/Presentation/V3/Strings/LabelValuePair.cs
index 58ee501..ede598a 100644
--- a/src/IIIF/IIIF/Presentation/V3/Strings/LabelValuePair.cs
+++ b/src/IIIF/IIIF/Presentation/V3/Strings/LabelValuePair.cs
@@ -1,5 +1,4 @@
 using System.Linq;
-using Newtonsoft.Json;
 
 namespace IIIF.Presentation.V3.Strings;
 
diff --git a/src/IIIF/IIIF/Utils/CollectionX.cs b/src/IIIF/IIIF/Utils/CollectionX.cs
index 174dce0..42e40ac 100644
--- a/src/IIIF/IIIF/Utils/CollectionX.cs
+++ b/src/IIIF/IIIF/Utils/CollectionX.cs
@@ -1,10 +1,11 @@
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 
 namespace IIIF.Utils;
 
 internal static class CollectionX
 {
-    public static bool IsNullOrEmpty<T>(this List<T> collection)
+    public static bool IsNullOrEmpty<T>([NotNullWhen(false)] this List<T>? collection)
     {
         return collection == null || collection.Count == 0;
     }