diff --git a/src/Jackett/Indexers/Abstract/GazelleTracker.cs b/src/Jackett/Indexers/Abstract/GazelleTracker.cs
index fd51707d3..95b2c02b2 100644
--- a/src/Jackett/Indexers/Abstract/GazelleTracker.cs
+++ b/src/Jackett/Indexers/Abstract/GazelleTracker.cs
@@ -132,7 +132,7 @@ namespace Jackett.Indexers.Abstract
                         release.Title += " [" + releaseType + "]";
 
                     release.Description = "";
-                    if (tags != null)
+                    if (tags != null && tags.Count > 0 && (string)tags[0] != "")
                         release.Description += "Tags: " + string.Join(", ", tags) + "\n";
 
                     if (r["torrents"] is JArray)
@@ -141,13 +141,15 @@ namespace Jackett.Indexers.Abstract
                         {
                             ReleaseInfo release2 = (ReleaseInfo)release.Clone();
                             FillReleaseInfoFromJson(release2, torrent);
-                            releases.Add(release2);
+                            if (ReleaseInfoPostParse(release2, torrent, r))
+                                releases.Add(release2);
                         }
                     }
                     else
                     {
                         FillReleaseInfoFromJson(release, r);
-                        releases.Add(release);
+                        if (ReleaseInfoPostParse(release, r, r))
+                            releases.Add(release);
                     }
                 }
             }
@@ -159,6 +161,12 @@ namespace Jackett.Indexers.Abstract
             return releases;
         }
 
+        // hook to add/modify the parsed information, return false to exclude the torrent from the results
+        protected virtual bool ReleaseInfoPostParse(ReleaseInfo release, JObject torrent, JObject result)
+        {
+            return true;
+        }
+
         void FillReleaseInfoFromJson(ReleaseInfo release, JObject torrent)
         {
             var torrentId = torrent["torrentId"];
diff --git a/src/Jackett/Indexers/BaseIndexer.cs b/src/Jackett/Indexers/BaseIndexer.cs
index 036978a15..afaf103b9 100644
--- a/src/Jackett/Indexers/BaseIndexer.cs
+++ b/src/Jackett/Indexers/BaseIndexer.cs
@@ -124,7 +124,7 @@ namespace Jackett.Indexers
         {
             if (null != input)
             {
-                var mapping = categoryMapping.Where(m => m.TrackerCategory.ToLowerInvariant() == input.ToLowerInvariant()).FirstOrDefault();
+                var mapping = categoryMapping.Where(m => m.TrackerCategory != null && m.TrackerCategory.ToLowerInvariant() == input.ToLowerInvariant()).FirstOrDefault();
                 if (mapping != null)
                 {
                     return mapping.NewzNabCategory;
@@ -137,7 +137,7 @@ namespace Jackett.Indexers
         {
             if (null != input)
             {
-                var mapping = categoryMapping.Where(m => m.TrackerCategoryDesc.ToLowerInvariant() == input.ToLowerInvariant()).FirstOrDefault();
+                var mapping = categoryMapping.Where(m => m.TrackerCategoryDesc != null && m.TrackerCategoryDesc.ToLowerInvariant() == input.ToLowerInvariant()).FirstOrDefault();
                 if (mapping != null)
                 {
                     return mapping.NewzNabCategory;
@@ -560,7 +560,7 @@ namespace Jackett.Indexers
             }
         }
 
-        protected List<string> MapTorznabCapsToTrackers(TorznabQuery query, bool mapChildrenCatsToParent = false)
+        protected virtual List<string> MapTorznabCapsToTrackers(TorznabQuery query, bool mapChildrenCatsToParent = false)
         {
             var result = new List<string>();
             foreach (var cat in query.Categories)
diff --git a/src/Jackett/Indexers/HDOnly.cs b/src/Jackett/Indexers/HDOnly.cs
new file mode 100644
index 000000000..93b2d98c8
--- /dev/null
+++ b/src/Jackett/Indexers/HDOnly.cs
@@ -0,0 +1,63 @@
+using Jackett.Models;
+using NLog;
+using Jackett.Services;
+using Jackett.Utils.Clients;
+using Jackett.Indexers.Abstract;
+using Newtonsoft.Json.Linq;
+using System.Collections.Generic;
+using System.Web;
+
+namespace Jackett.Indexers
+{
+    public class HDOnly : GazelleTracker, IIndexer
+    {
+        public HDOnly(IIndexerManagerService indexerManager, IWebClient webClient, Logger logger, IProtectionService protectionService)
+            : base(name: "HD-Only",
+                desc: null,
+                link: "https://hd-only.org/",
+                indexerManager: indexerManager,
+                logger: logger,
+                protectionService: protectionService,
+                webClient: webClient
+                )
+        {
+            Language = "fr-fr";
+            Type = "private";
+
+            // a few releases have "category":"S\u00e9ries" set
+            AddCategoryMapping(null, TorznabCatType.TV, "Séries");
+
+            // releaseType mappings
+            AddCategoryMapping(1, TorznabCatType.Movies, "Film");
+            AddCategoryMapping(3, TorznabCatType.TVAnime, "Dessin animé");
+            AddCategoryMapping(5, TorznabCatType.TV, "Série");
+            AddCategoryMapping(6, TorznabCatType.TVAnime, "Série Animée");
+            AddCategoryMapping(7, TorznabCatType.MoviesOther, "Film d'animation");
+            AddCategoryMapping(9, TorznabCatType.AudioVideo, "Concert");
+            AddCategoryMapping(11, TorznabCatType.TVDocumentary, "Documentaire");
+            AddCategoryMapping(13, TorznabCatType.MoviesOther, "Court-métrage");
+            AddCategoryMapping(14, TorznabCatType.MoviesOther, "Clip");
+            AddCategoryMapping(15, TorznabCatType.MoviesOther, "Démonstration");
+            AddCategoryMapping(16, TorznabCatType.MoviesOther, "Bonus de BD");
+            AddCategoryMapping(21, TorznabCatType.Other, "Autre");
+        }
+
+        protected override bool ReleaseInfoPostParse(ReleaseInfo release, JObject torrent, JObject result)
+        {
+            // releaseType is used for categories
+            var category = (string)result["category"];
+            if (category == null)
+            {
+                var releaseType = (string)result["releaseType"];
+                release.Category = MapTrackerCatDescToNewznab(releaseType);
+            }
+            return true;
+        }
+
+        protected override List<string> MapTorznabCapsToTrackers(TorznabQuery query, bool mapChildrenCatsToParent = false)
+        {
+            // don't use category filtering
+            return new List<string>();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Jackett/Jackett.csproj b/src/Jackett/Jackett.csproj
index aaad49db2..4e7c80e51 100644
--- a/src/Jackett/Jackett.csproj
+++ b/src/Jackett/Jackett.csproj
@@ -178,6 +178,7 @@
     <Compile Include="Controllers\TorznabController.cs" />
     <Compile Include="Controllers\DownloadController.cs" />
     <Compile Include="Engine.cs" />
+    <Compile Include="Indexers\HDOnly.cs" />
     <Compile Include="Indexers\PiXELHD.cs" />
     <Compile Include="Indexers\Hardbay.cs" />
     <Compile Include="Indexers\Rarbg.cs" />