diff --git a/SabreTools.Core/Tools/Converters.cs b/SabreTools.Core/Tools/Converters.cs
index bb4c10bd..1e08106e 100644
--- a/SabreTools.Core/Tools/Converters.cs
+++ b/SabreTools.Core/Tools/Converters.cs
@@ -1727,9 +1727,9 @@ namespace SabreTools.Core.Tools
         {
             return supported switch
             {
-                Supported.No => "no",
+                Supported.No => verbose ? "unsupported" : "no",
                 Supported.Partial => "partial",
-                Supported.Yes => "yes",
+                Supported.Yes => verbose ? "supported" : "yes",
                 _ => null,
             };
         }
diff --git a/SabreTools.DatFiles/DatFile.cs b/SabreTools.DatFiles/DatFile.cs
index f95839bc..b3077741 100644
--- a/SabreTools.DatFiles/DatFile.cs
+++ b/SabreTools.DatFiles/DatFile.cs
@@ -70,88 +70,37 @@ namespace SabreTools.DatFiles
         /// <returns>DatFile of the specific internal type that corresponds to the inputs</returns>
         public static DatFile Create(DatFormat? datFormat = null, DatFile baseDat = null, bool quotes = true)
         {
-            switch (datFormat)
+            return datFormat switch
             {
-                case DatFormat.AttractMode:
-                    return new AttractMode(baseDat);
-
-                case DatFormat.ClrMamePro:
-                    return new ClrMamePro(baseDat, quotes);
-
-                case DatFormat.CSV:
-                    return new Formats.SeparatedValue(baseDat, ',');
-
-                case DatFormat.DOSCenter:
-                    return new DosCenter(baseDat);
-
-                case DatFormat.EverdriveSMDB:
-                    return new EverdriveSMDB(baseDat);
-
-                case DatFormat.Listrom:
-                    return new Listrom(baseDat);
-
-                case DatFormat.Listxml:
-                    return new Listxml(baseDat);
-
-                case DatFormat.Logiqx:
-                    return new Logiqx(baseDat, false);
-
-                case DatFormat.LogiqxDeprecated:
-                    return new Logiqx(baseDat, true);
-
-                case DatFormat.MissFile:
-                    return new Missfile(baseDat);
-
-                case DatFormat.OfflineList:
-                    return new OfflineList(baseDat);
-
-                case DatFormat.OpenMSX:
-                    return new OpenMSX(baseDat);
-
-                case DatFormat.RedumpMD5:
-                    return new Hashfile(baseDat, Hash.MD5);
-
-                case DatFormat.RedumpSFV:
-                    return new Hashfile(baseDat, Hash.CRC);
-
-                case DatFormat.RedumpSHA1:
-                    return new Hashfile(baseDat, Hash.SHA1);
-
-                case DatFormat.RedumpSHA256:
-                    return new Hashfile(baseDat, Hash.SHA256);
-
-                case DatFormat.RedumpSHA384:
-                    return new Hashfile(baseDat, Hash.SHA384);
-
-                case DatFormat.RedumpSHA512:
-                    return new Hashfile(baseDat, Hash.SHA512);
-
-                case DatFormat.RedumpSpamSum:
-                    return new Hashfile(baseDat, Hash.SpamSum);
-
-                case DatFormat.RomCenter:
-                    return new RomCenter(baseDat);
-
-                case DatFormat.SabreJSON:
-                    return new SabreJSON(baseDat);
-
-                case DatFormat.SabreXML:
-                    return new SabreXML(baseDat);
-
-                case DatFormat.SoftwareList:
-                    return new Formats.SoftwareList(baseDat);
-
-                case DatFormat.SSV:
-                    return new Formats.SeparatedValue(baseDat, ';');
-
-                case DatFormat.TSV:
-                    return new Formats.SeparatedValue(baseDat, '\t');
-
+                DatFormat.AttractMode => new AttractMode(baseDat),
+                DatFormat.ClrMamePro => new ClrMamePro(baseDat, quotes),
+                DatFormat.CSV => new SeparatedValue(baseDat, ','),
+                DatFormat.DOSCenter => new DosCenter(baseDat),
+                DatFormat.EverdriveSMDB => new EverdriveSMDB(baseDat),
+                DatFormat.Listrom => new Listrom(baseDat),
+                DatFormat.Listxml => new Listxml(baseDat),
+                DatFormat.Logiqx => new Logiqx(baseDat, false),
+                DatFormat.LogiqxDeprecated => new Logiqx(baseDat, true),
+                DatFormat.MissFile => new Missfile(baseDat),
+                DatFormat.OfflineList => new OfflineList(baseDat),
+                DatFormat.OpenMSX => new OpenMSX(baseDat),
+                DatFormat.RedumpMD5 => new Hashfile(baseDat, Hash.MD5),
+                DatFormat.RedumpSFV => new Hashfile(baseDat, Hash.CRC),
+                DatFormat.RedumpSHA1 => new Hashfile(baseDat, Hash.SHA1),
+                DatFormat.RedumpSHA256 => new Hashfile(baseDat, Hash.SHA256),
+                DatFormat.RedumpSHA384 => new Hashfile(baseDat, Hash.SHA384),
+                DatFormat.RedumpSHA512 => new Hashfile(baseDat, Hash.SHA512),
+                DatFormat.RedumpSpamSum => new Hashfile(baseDat, Hash.SpamSum),
+                DatFormat.RomCenter => new RomCenter(baseDat),
+                DatFormat.SabreJSON => new SabreJSON(baseDat),
+                DatFormat.SabreXML => new SabreXML(baseDat),
+                DatFormat.SoftwareList => new Formats.SoftwareList(baseDat),
+                DatFormat.SSV => new SeparatedValue(baseDat, ';'),
+                DatFormat.TSV => new SeparatedValue(baseDat, '\t'),
+                
                 // We use new-style Logiqx as a backup for generic DatFile
-                case null:
-                default:
-                    return new Logiqx(baseDat, false);
-            }
+                _ => new Logiqx(baseDat, false),
+            };
         }
 
         /// <summary>
@@ -213,7 +162,7 @@ namespace SabreTools.DatFiles
         /// <returns>The key for the item</returns>
         protected string ParseAddHelper(DatItem item)
         {
-            string key = string.Empty;
+            string key;
 
             // If we have a Disk, Media, or Rom, clean the hash data
             if (item.ItemType == ItemType.Disk)
@@ -344,7 +293,7 @@ namespace SabreTools.DatFiles
         protected string CreatePrefixPostfix(DatItem item, bool prefix)
         {
             // Initialize strings
-            string fix = string.Empty,
+            string fix,
                 game = item.Machine.Name,
                 name = item.GetName() ?? item.ItemType.ToString(),
                 crc = string.Empty,
diff --git a/SabreTools.DatFiles/Formats/EverdriveSmdb.cs b/SabreTools.DatFiles/Formats/EverdriveSmdb.cs
index 739172f6..1a0317ef 100644
--- a/SabreTools.DatFiles/Formats/EverdriveSmdb.cs
+++ b/SabreTools.DatFiles/Formats/EverdriveSmdb.cs
@@ -69,7 +69,7 @@ namespace SabreTools.DatFiles.Formats
 
                     Rom rom = new Rom
                     {
-                        Name = svr.Line[1].Substring(fullname[0].Length + 1),
+                        Name = svr.Line[1][(fullname[0].Length + 1)..],
                         Size = null, // No size provided, but we don't want the size being 0
                         CRC = svr.Line[4],
                         MD5 = svr.Line[3],
diff --git a/SabreTools.DatFiles/Formats/Hashfile.cs b/SabreTools.DatFiles/Formats/Hashfile.cs
index f22dd9da..f03d97b5 100644
--- a/SabreTools.DatFiles/Formats/Hashfile.cs
+++ b/SabreTools.DatFiles/Formats/Hashfile.cs
@@ -222,7 +222,7 @@ namespace SabreTools.DatFiles.Formats
             }
 
             // Get the hash field and set final fields
-            string hash = string.Empty;
+            string hash;
             switch (_hash)
             {
                 case Hash.CRC:
diff --git a/SabreTools.DatFiles/Formats/Listrom.cs b/SabreTools.DatFiles/Formats/Listrom.cs
index 37386791..e8f19bf2 100644
--- a/SabreTools.DatFiles/Formats/Listrom.cs
+++ b/SabreTools.DatFiles/Formats/Listrom.cs
@@ -93,7 +93,7 @@ namespace SabreTools.DatFiles.Formats
                             logger.Warning($"Possibly malformed line: '{line}'");
 
                         string romname = split[0];
-                        line = line.Substring(romname.Length);
+                        line = line[romname.Length..];
 
                         // Next we separate the ROM into pieces
                         split = line.Split(new char[0], StringSplitOptions.RemoveEmptyEntries);
diff --git a/SabreTools.DatFiles/Formats/Logiqx.cs b/SabreTools.DatFiles/Formats/Logiqx.cs
index 656e5463..7cd3967f 100644
--- a/SabreTools.DatFiles/Formats/Logiqx.cs
+++ b/SabreTools.DatFiles/Formats/Logiqx.cs
@@ -398,8 +398,6 @@ namespace SabreTools.DatFiles.Formats
             // Otherwise, add what is possible
             reader.MoveToContent();
 
-            string key = string.Empty;
-            string temptype = reader.Name;
             bool containsItems = false;
 
             // Create a new machine
@@ -497,7 +495,7 @@ namespace SabreTools.DatFiles.Formats
                         archive.CopyMachineInformation(machine);
 
                         // Now process and add the archive
-                        key = ParseAddHelper(archive);
+                        ParseAddHelper(archive);
 
                         reader.Read();
                         break;
@@ -521,7 +519,7 @@ namespace SabreTools.DatFiles.Formats
                         biosSet.CopyMachineInformation(machine);
 
                         // Now process and add the biosSet
-                        key = ParseAddHelper(biosSet);
+                        ParseAddHelper(biosSet);
 
                         reader.Read();
                         break;
@@ -547,7 +545,7 @@ namespace SabreTools.DatFiles.Formats
                         disk.CopyMachineInformation(machine);
 
                         // Now process and add the disk
-                        key = ParseAddHelper(disk);
+                        ParseAddHelper(disk);
 
                         reader.Read();
                         break;
@@ -573,7 +571,7 @@ namespace SabreTools.DatFiles.Formats
                         media.CopyMachineInformation(machine);
 
                         // Now process and add the media
-                        key = ParseAddHelper(media);
+                        ParseAddHelper(media);
 
                         reader.Read();
                         break;
@@ -593,7 +591,7 @@ namespace SabreTools.DatFiles.Formats
                         release.CopyMachineInformation(machine);
 
                         // Now process and add the release
-                        key = ParseAddHelper(release);
+                        ParseAddHelper(release);
 
                         reader.Read();
                         break;
@@ -627,7 +625,7 @@ namespace SabreTools.DatFiles.Formats
                         rom.CopyMachineInformation(machine);
 
                         // Now process and add the rom
-                        key = ParseAddHelper(rom);
+                        ParseAddHelper(rom);
 
                         reader.Read();
                         break;
@@ -649,7 +647,7 @@ namespace SabreTools.DatFiles.Formats
                         sample.CopyMachineInformation(machine);
 
                         // Now process and add the sample
-                        key = ParseAddHelper(sample);
+                        ParseAddHelper(sample);
 
                         reader.Read();
                         break;
diff --git a/SabreTools.DatFiles/Formats/SabreJSON.cs b/SabreTools.DatFiles/Formats/SabreJSON.cs
index 1235a236..1c0cd99b 100644
--- a/SabreTools.DatFiles/Formats/SabreJSON.cs
+++ b/SabreTools.DatFiles/Formats/SabreJSON.cs
@@ -536,7 +536,7 @@ namespace SabreTools.DatFiles.Formats
                 return base.CreateProperties(type, memberSerialization)
                     .OrderBy(p => BaseTypesAndSelf(p.DeclaringType).Count()).ToList();
 
-                IEnumerable<Type> BaseTypesAndSelf(Type t)
+                static IEnumerable<Type> BaseTypesAndSelf(Type t)
                 {
                     while (t != null)
                     {
diff --git a/SabreTools.DatFiles/ItemDictionary.cs b/SabreTools.DatFiles/ItemDictionary.cs
index c8466a1b..f6ee638b 100644
--- a/SabreTools.DatFiles/ItemDictionary.cs
+++ b/SabreTools.DatFiles/ItemDictionary.cs
@@ -34,7 +34,7 @@ namespace SabreTools.DatFiles
         /// <summary>
         /// Internal dictionary for the class
         /// </summary>
-        private ConcurrentDictionary<string, List<DatItem>> items;
+        private readonly ConcurrentDictionary<string, List<DatItem>> items;
 
         /// <summary>
         /// Lock for statistics calculation
@@ -44,12 +44,7 @@ namespace SabreTools.DatFiles
         /// <summary>
         /// Logging object
         /// </summary>
-        private Logger logger;
-
-        /// <summary>
-        /// Static logger for static methods
-        /// </summary>
-        private static Logger staticLogger = new Logger();
+        private readonly Logger logger;
 
         #endregion
 
diff --git a/SabreTools.DatItems/Disk.cs b/SabreTools.DatItems/Disk.cs
index 7a0c9109..34d3f1bd 100644
--- a/SabreTools.DatItems/Disk.cs
+++ b/SabreTools.DatItems/Disk.cs
@@ -370,7 +370,7 @@ namespace SabreTools.DatItems
         public override string GetKey(ItemKey bucketedBy, bool lower = true, bool norename = true)
         {
             // Set the output key as the default blank string
-            string key = string.Empty;
+            string key;
 
             // Now determine what the key should be based on the bucketedBy value
             switch (bucketedBy)
diff --git a/SabreTools.DatItems/Media.cs b/SabreTools.DatItems/Media.cs
index 700f61b1..63784be0 100644
--- a/SabreTools.DatItems/Media.cs
+++ b/SabreTools.DatItems/Media.cs
@@ -293,7 +293,7 @@ namespace SabreTools.DatItems
         public override string GetKey(ItemKey bucketedBy, bool lower = true, bool norename = true)
         {
             // Set the output key as the default blank string
-            string key = string.Empty;
+            string key;
 
             // Now determine what the key should be based on the bucketedBy value
             switch (bucketedBy)
diff --git a/SabreTools.DatItems/Rom.cs b/SabreTools.DatItems/Rom.cs
index d74b4737..60f6cda1 100644
--- a/SabreTools.DatItems/Rom.cs
+++ b/SabreTools.DatItems/Rom.cs
@@ -629,7 +629,7 @@ namespace SabreTools.DatItems
         public override string GetKey(ItemKey bucketedBy, bool lower = true, bool norename = true)
         {
             // Set the output key as the default blank string
-            string key = string.Empty;
+            string key;
 
             // Now determine what the key should be based on the bucketedBy value
             switch (bucketedBy)
diff --git a/SabreTools.DatTools/DatFromDir.cs b/SabreTools.DatTools/DatFromDir.cs
index 361a16ee..de1cbe32 100644
--- a/SabreTools.DatTools/DatFromDir.cs
+++ b/SabreTools.DatTools/DatFromDir.cs
@@ -415,22 +415,22 @@ namespace SabreTools.DatTools
             // If we have a Disk, then the ".chd" extension needs to be removed
             if (datItem.ItemType == ItemType.Disk && itemName.EndsWith(".chd"))
             {
-                itemName = itemName.Substring(0, itemName.Length - 4);
+                itemName = itemName[0..^4];
             }
 
             // If we have a Media, then the extension needs to be removed
             else if (datItem.ItemType == ItemType.Media)
             {
                 if (itemName.EndsWith(".dicf"))
-                    itemName = itemName.Substring(0, itemName.Length - 5);
+                    itemName = itemName[0..^5];
                 else if (itemName.EndsWith(".aaru"))
-                    itemName = itemName.Substring(0, itemName.Length - 5);
+                    itemName = itemName[0..^5];
                 else if (itemName.EndsWith(".aaruformat"))
-                    itemName = itemName.Substring(0, itemName.Length - 11);
+                    itemName = itemName[0..^11];
                 else if (itemName.EndsWith(".aaruf"))
-                    itemName = itemName.Substring(0, itemName.Length - 6);
+                    itemName = itemName[0..^6];
                 else if (itemName.EndsWith(".aif"))
-                    itemName = itemName.Substring(0, itemName.Length - 4);
+                    itemName = itemName[0..^4];
             }
 
             // Set the item name back
diff --git a/SabreTools.DatTools/Parser.cs b/SabreTools.DatTools/Parser.cs
index ad18201a..04621e39 100644
--- a/SabreTools.DatTools/Parser.cs
+++ b/SabreTools.DatTools/Parser.cs
@@ -158,23 +158,21 @@ namespace SabreTools.DatTools
 
             try
             {
-                using (StreamReader sr = File.OpenText(filename))
+                using StreamReader sr = File.OpenText(filename);
+                first = sr.ReadLine().ToLowerInvariant();
+                while ((string.IsNullOrWhiteSpace(first) || first.StartsWith("<!--"))
+                    && !sr.EndOfStream)
                 {
                     first = sr.ReadLine().ToLowerInvariant();
-                    while ((string.IsNullOrWhiteSpace(first) || first.StartsWith("<!--"))
+                }
+
+                if (!sr.EndOfStream)
+                {
+                    second = sr.ReadLine().ToLowerInvariant();
+                    while (string.IsNullOrWhiteSpace(second) || second.StartsWith("<!--")
                         && !sr.EndOfStream)
-                    {
-                        first = sr.ReadLine().ToLowerInvariant();
-                    }
-
-                    if (!sr.EndOfStream)
                     {
                         second = sr.ReadLine().ToLowerInvariant();
-                        while (string.IsNullOrWhiteSpace(second) || second.StartsWith("<!--")
-                            && !sr.EndOfStream)
-                        {
-                            second = sr.ReadLine().ToLowerInvariant();
-                        }
                     }
                 }
             }
diff --git a/SabreTools.FileTypes/Aaru/AaruFormat.cs b/SabreTools.FileTypes/Aaru/AaruFormat.cs
index c92333ca..f5418033 100644
--- a/SabreTools.FileTypes/Aaru/AaruFormat.cs
+++ b/SabreTools.FileTypes/Aaru/AaruFormat.cs
@@ -46,10 +46,8 @@ namespace SabreTools.FileTypes.Aaru
         /// <param name="filename">Filename respresenting the AaruFormat file</param>
         public static AaruFormat Create(string filename)
         {
-            using (FileStream fs = File.OpenRead(filename))
-            {
-                return Create(fs);
-            }
+            using FileStream fs = File.OpenRead(filename);
+            return Create(fs);
         }
 
         /// <summary>
diff --git a/SabreTools.FileTypes/Archives/GZipArchive.cs b/SabreTools.FileTypes/Archives/GZipArchive.cs
index 57c45b5f..77e48eb6 100644
--- a/SabreTools.FileTypes/Archives/GZipArchive.cs
+++ b/SabreTools.FileTypes/Archives/GZipArchive.cs
@@ -227,12 +227,11 @@ namespace SabreTools.FileTypes.Archives
                         if (this.AvailableHashes == Hash.CRC)
                         {
                             gzipEntryRom.Filename = gamename;
-                            using (BinaryReader br = new BinaryReader(File.OpenRead(this.Filename)))
-                            {
-                                br.BaseStream.Seek(-8, SeekOrigin.End);
-                                gzipEntryRom.CRC = br.ReadBytesBigEndian(4);
-                                gzipEntryRom.Size = br.ReadInt32BigEndian();
-                            }
+                            
+                            using BinaryReader br = new BinaryReader(File.OpenRead(this.Filename));
+                            br.BaseStream.Seek(-8, SeekOrigin.End);
+                            gzipEntryRom.CRC = br.ReadBytesBigEndian(4);
+                            gzipEntryRom.Size = br.ReadInt32BigEndian();
                         }
                         // Otherwise, use the stream directly
                         else
diff --git a/SabreTools.FileTypes/Archives/RarArchive.cs b/SabreTools.FileTypes/Archives/RarArchive.cs
index caca4ce2..d28e3632 100644
--- a/SabreTools.FileTypes/Archives/RarArchive.cs
+++ b/SabreTools.FileTypes/Archives/RarArchive.cs
@@ -178,10 +178,8 @@ namespace SabreTools.FileTypes.Archives
                     // Otherwise, use the stream directly
                     else
                     {
-                        using (Stream entryStream = entry.OpenEntryStream())
-                        {
-                            rarEntryRom = GetInfo(entryStream, size: entry.Size, hashes: this.AvailableHashes);
-                        }
+                        using Stream entryStream = entry.OpenEntryStream();
+                        rarEntryRom = GetInfo(entryStream, size: entry.Size, hashes: this.AvailableHashes);
                     }
 
                     // Fill in comon details and add to the list
diff --git a/SabreTools.FileTypes/Archives/TapeArchive.cs b/SabreTools.FileTypes/Archives/TapeArchive.cs
index cae90b68..f7e78e22 100644
--- a/SabreTools.FileTypes/Archives/TapeArchive.cs
+++ b/SabreTools.FileTypes/Archives/TapeArchive.cs
@@ -183,10 +183,8 @@ namespace SabreTools.FileTypes.Archives
                     // Otherwise, use the stream directly
                     else
                     {
-                        using (Stream entryStream = entry.OpenEntryStream())
-                        {
-                            tarEntryRom = GetInfo(entryStream, size: entry.Size, hashes: this.AvailableHashes);
-                        }
+                        using Stream entryStream = entry.OpenEntryStream();
+                        tarEntryRom = GetInfo(entryStream, size: entry.Size, hashes: this.AvailableHashes);
                     }
 
                     // Fill in comon details and add to the list
diff --git a/SabreTools.FileTypes/Archives/XZArchive.cs b/SabreTools.FileTypes/Archives/XZArchive.cs
index 0a01d113..748c0749 100644
--- a/SabreTools.FileTypes/Archives/XZArchive.cs
+++ b/SabreTools.FileTypes/Archives/XZArchive.cs
@@ -211,12 +211,11 @@ namespace SabreTools.FileTypes.Archives
                         if (this.AvailableHashes == Hash.CRC)
                         {
                             xzEntryRom.Filename = gamename;
-                            using (BinaryReader br = new BinaryReader(File.OpenRead(this.Filename)))
-                            {
-                                br.BaseStream.Seek(-8, SeekOrigin.End);
-                                xzEntryRom.CRC = br.ReadBytesBigEndian(4);
-                                xzEntryRom.Size = br.ReadInt32BigEndian();
-                            }
+                            
+                            using BinaryReader br = new BinaryReader(File.OpenRead(this.Filename));
+                            br.BaseStream.Seek(-8, SeekOrigin.End);
+                            xzEntryRom.CRC = br.ReadBytesBigEndian(4);
+                            xzEntryRom.Size = br.ReadInt32BigEndian();
                         }
                         // Otherwise, use the stream directly
                         else
diff --git a/SabreTools.FileTypes/BaseArchive.cs b/SabreTools.FileTypes/BaseArchive.cs
index 0ca94b02..b8c10229 100644
--- a/SabreTools.FileTypes/BaseArchive.cs
+++ b/SabreTools.FileTypes/BaseArchive.cs
@@ -99,26 +99,15 @@ namespace SabreTools.FileTypes
         /// <returns>Archive object representing the inputs</returns>
         public static BaseArchive Create(FileType archiveType)
         {
-            switch (archiveType)
+            return archiveType switch
             {
-                case FileType.GZipArchive:
-                    return new GZipArchive();
-
-                case FileType.RarArchive:
-                    return new RarArchive();
-
-                case FileType.SevenZipArchive:
-                    return new SevenZipArchive();
-
-                case FileType.TapeArchive:
-                    return new TapeArchive();
-
-                case FileType.ZipArchive:
-                    return new ZipArchive();
-
-                default:
-                    return null;
-            }
+                FileType.GZipArchive => new GZipArchive(),
+                FileType.RarArchive => new RarArchive(),
+                FileType.SevenZipArchive => new SevenZipArchive(),
+                FileType.TapeArchive => new TapeArchive(),
+                FileType.ZipArchive => new ZipArchive(),
+                _ => null,
+            };
         }
 
         #endregion
diff --git a/SabreTools.FileTypes/CHD/CHDFile.cs b/SabreTools.FileTypes/CHD/CHDFile.cs
index 8a550346..76b5dfba 100644
--- a/SabreTools.FileTypes/CHD/CHDFile.cs
+++ b/SabreTools.FileTypes/CHD/CHDFile.cs
@@ -29,10 +29,8 @@ namespace SabreTools.FileTypes.CHD
         /// <param name="filename">Filename respresenting the CHD file</param>
         public static CHDFile Create(string filename)
         {
-            using (FileStream fs = File.OpenRead(filename))
-            {
-                return Create(fs);
-            }
+            using FileStream fs = File.OpenRead(filename);
+            return Create(fs);
         }
 
         /// <summary>
@@ -108,21 +106,15 @@ namespace SabreTools.FileTypes.CHD
             if (!string.Equals(new string(tag), "MComprHD", StringComparison.Ordinal))
                 return 0;
 
-            switch (version)
+            return version switch
             {
-                case 1:
-                    return length == CHDFileV1.HeaderSize ? version : 0;
-                case 2:
-                    return length == CHDFileV2.HeaderSize ? version : 0;
-                case 3:
-                    return length == CHDFileV3.HeaderSize ? version : 0;
-                case 4:
-                    return length == CHDFileV4.HeaderSize ? version : 0;
-                case 5:
-                    return length == CHDFileV5.HeaderSize ? version : 0;
-                default:
-                    return 0;
-            }
+                1 => length == CHDFileV1.HeaderSize ? version : 0,
+                2 => length == CHDFileV2.HeaderSize ? version : 0,
+                3 => length == CHDFileV3.HeaderSize ? version : 0,
+                4 => length == CHDFileV4.HeaderSize ? version : 0,
+                5 => length == CHDFileV5.HeaderSize ? version : 0,
+                _ => 0,
+            };
         }
 
         /// <summary>
@@ -133,21 +125,15 @@ namespace SabreTools.FileTypes.CHD
         /// <returns>Populated CHD file, null on failure</returns>
         private static CHDFile ReadAsVersion(Stream stream, uint version)
         {
-            switch (version)
+            return version switch
             {
-                case 1:
-                    return CHDFileV1.Deserialize(stream);
-                case 2:
-                    return CHDFileV2.Deserialize(stream);
-                case 3:
-                    return CHDFileV3.Deserialize(stream);
-                case 4:
-                    return CHDFileV4.Deserialize(stream);
-                case 5:
-                    return CHDFileV5.Deserialize(stream);
-                default:
-                    return null;
-            }
+                1 => CHDFileV1.Deserialize(stream),
+                2 => CHDFileV2.Deserialize(stream),
+                3 => CHDFileV3.Deserialize(stream),
+                4 => CHDFileV4.Deserialize(stream),
+                5 => CHDFileV5.Deserialize(stream),
+                _ => null,
+            };
         }
 
         #endregion
diff --git a/SabreTools.FileTypes/Folder.cs b/SabreTools.FileTypes/Folder.cs
index c4693555..7460c031 100644
--- a/SabreTools.FileTypes/Folder.cs
+++ b/SabreTools.FileTypes/Folder.cs
@@ -32,7 +32,7 @@ namespace SabreTools.FileTypes
         /// <summary>
         /// Flag specific to Folder to omit Machine name from output path
         /// </summary>
-        private bool writeToParent = false;
+        private readonly bool writeToParent = false;
 
         #endregion
 
diff --git a/SabreTools.Filtering/ExtraIni.cs b/SabreTools.Filtering/ExtraIni.cs
index 4b76efcc..cb9653b8 100644
--- a/SabreTools.Filtering/ExtraIni.cs
+++ b/SabreTools.Filtering/ExtraIni.cs
@@ -58,7 +58,7 @@ namespace SabreTools.Filtering
 
                 string inputTrimmed = input.Trim('"', ' ', '\t');
                 string fieldString = inputTrimmed.Split(':')[0].ToLowerInvariant().Trim('"', ' ', '\t');
-                string fileString = inputTrimmed.Substring(fieldString.Length + 1).Trim('"', ' ', '\t');
+                string fileString = inputTrimmed[(fieldString.Length + 1)..].Trim('"', ' ', '\t');
 
                 item.DatItemField = fieldString.AsDatItemField();
                 item.MachineField = fieldString.AsMachineField();
diff --git a/SabreTools.Filtering/Filter.cs b/SabreTools.Filtering/Filter.cs
index 1d570816..0294eeeb 100644
--- a/SabreTools.Filtering/Filter.cs
+++ b/SabreTools.Filtering/Filter.cs
@@ -57,10 +57,10 @@ namespace SabreTools.Filtering
                 || filterTrimmed.StartsWith("~")
                 || filterTrimmed.StartsWith("not-");
             filterTrimmed = filterTrimmed.TrimStart('!', '~');
-            filterTrimmed = filterTrimmed.StartsWith("not-") ? filterTrimmed.Substring(4) : filterTrimmed;
+            filterTrimmed = filterTrimmed.StartsWith("not-") ? filterTrimmed[4..] : filterTrimmed;
 
             string filterFieldString = filterTrimmed.Split(':')[0].ToLowerInvariant().Trim('"', ' ', '\t');
-            string filterValue = filterTrimmed.Substring(filterFieldString.Length + 1).Trim('"', ' ', '\t');
+            string filterValue = filterTrimmed[(filterFieldString.Length + 1)..].Trim('"', ' ', '\t');
         
             return (filterFieldString, filterValue, negate);
         }
diff --git a/SabreTools.Filtering/FilterItem.cs b/SabreTools.Filtering/FilterItem.cs
index 7eb395a1..b7a4a9e5 100644
--- a/SabreTools.Filtering/FilterItem.cs
+++ b/SabreTools.Filtering/FilterItem.cs
@@ -153,9 +153,8 @@ namespace SabreTools.Filtering
             {
                 if (straw is string)
                 {
-                    string needleString = needle as string;
                     string strawString = straw as string;
-                    if (!string.IsNullOrWhiteSpace(strawString) && needleString != null)
+                    if (!string.IsNullOrWhiteSpace(strawString) && needle is string needleString)
                     {
                         string regexStraw = strawString;
 
diff --git a/SabreTools.Help/FeatureSet.cs b/SabreTools.Help/FeatureSet.cs
index a79534d5..5b9a2da7 100644
--- a/SabreTools.Help/FeatureSet.cs
+++ b/SabreTools.Help/FeatureSet.cs
@@ -8,9 +8,9 @@ namespace SabreTools.Help
     {
         #region Private variables
 
-        private List<string> _header;
+        private readonly List<string> _header;
         private Dictionary<string, Feature> _features;
-        private static string _barrier = "-----------------------------------------";
+        private const string _barrier = "-----------------------------------------";
 
         #endregion
 
@@ -155,16 +155,18 @@ namespace SabreTools.Help
         /// </summary>
         public void OutputCredits()
         {
-            List<string> credits = new List<string>();
-            credits.Add(_barrier);
-            credits.Add("Credits");
-            credits.Add(_barrier);
-            credits.Add(string.Empty);
-            credits.Add("Programmer / Lead:	Matt Nadareski (darksabre76)");
-            credits.Add("Additional code:	emuLOAD, @tractivo, motoschifo");
-            credits.Add("Testing:		emuLOAD, @tractivo, Kludge, Obiwantje, edc");
-            credits.Add("Suggestions:		edc, AcidX, Amiga12, EliUmniCk");
-            credits.Add("Based on work by:	The Wizard of DATz");
+            List<string> credits = new List<string>
+            {
+                _barrier,
+                "Credits",
+                _barrier,
+                string.Empty,
+                "Programmer / Lead:	Matt Nadareski (darksabre76)",
+                "Additional code:	emuLOAD, @tractivo, motoschifo",
+                "Testing:		emuLOAD, @tractivo, Kludge, Obiwantje, edc",
+                "Suggestions:		edc, AcidX, Amiga12, EliUmniCk",
+                "Based on work by:	The Wizard of DATz"
+            };
             WriteOutWithPauses(credits);
         }
 
diff --git a/SabreTools.IO/Readers/ClrMameProReader.cs b/SabreTools.IO/Readers/ClrMameProReader.cs
index d4aa4196..05648e53 100644
--- a/SabreTools.IO/Readers/ClrMameProReader.cs
+++ b/SabreTools.IO/Readers/ClrMameProReader.cs
@@ -125,7 +125,7 @@ namespace SabreTools.IO.Readers
             // Standalone (special case for DC dats)
             if (CurrentLine.StartsWith("Name:"))
             {
-                string temp = CurrentLine.Substring("Name:".Length).Trim();
+                string temp = CurrentLine["Name:".Length..].Trim();
                 CurrentLine = $"Name: {temp}";
             }
 
diff --git a/SabreTools.IO/Writers/ClrMameProWriter.cs b/SabreTools.IO/Writers/ClrMameProWriter.cs
index 980dc696..f3522f0e 100644
--- a/SabreTools.IO/Writers/ClrMameProWriter.cs
+++ b/SabreTools.IO/Writers/ClrMameProWriter.cs
@@ -59,7 +59,7 @@ namespace SabreTools.IO.Writers
         /// <summary>
         /// Internal stream writer
         /// </summary>
-        private StreamWriter sw;
+        private readonly StreamWriter sw;
 
         /// <summary>
         /// Stack for tracking current node
diff --git a/SabreTools.IO/Writers/IniWriter.cs b/SabreTools.IO/Writers/IniWriter.cs
index 9da83978..900870b1 100644
--- a/SabreTools.IO/Writers/IniWriter.cs
+++ b/SabreTools.IO/Writers/IniWriter.cs
@@ -9,7 +9,7 @@ namespace SabreTools.IO.Writers
         /// <summary>
         /// Internal stream writer for outputting
         /// </summary>
-        private StreamWriter sw;
+        private readonly StreamWriter sw;
 
         /// <summary>
         /// Constructor for writing to a file
diff --git a/SabreTools.IO/Writers/SeparatedValueWriter.cs b/SabreTools.IO/Writers/SeparatedValueWriter.cs
index c69832f7..9d3865c7 100644
--- a/SabreTools.IO/Writers/SeparatedValueWriter.cs
+++ b/SabreTools.IO/Writers/SeparatedValueWriter.cs
@@ -9,7 +9,7 @@ namespace SabreTools.IO.Writers
         /// <summary>
         /// Internal stream writer for outputting
         /// </summary>
-        private StreamWriter sw;
+        private readonly StreamWriter sw;
 
         /// <summary>
         /// Internal value if we've written a header before