diff --git a/src/SharpCompress/Archives/AbstractWritableArchive.cs b/src/SharpCompress/Archives/AbstractWritableArchive.cs
index ffc739ac9..67f822fd8 100644
--- a/src/SharpCompress/Archives/AbstractWritableArchive.cs
+++ b/src/SharpCompress/Archives/AbstractWritableArchive.cs
@@ -83,8 +83,8 @@ IArchiveEntry IWritableArchive.AddEntry(string key, Stream source, bool closeStr
         public TEntry AddEntry(string key, Stream source, bool closeStream,
                                long size = 0, DateTime? modified = null)
         {
-            if (key.StartsWith('/')
-                || key.StartsWith('\\'))
+            if (key.StartsWith("/")
+                || key.StartsWith("\\"))
             {
                 key = key.Substring(1);
             }
@@ -103,7 +103,7 @@ private bool DoesKeyMatchExisting(string key)
             foreach (var path in Entries.Select(x => x.Key))
             {
                 var p = path.Replace('/', '\\');
-                if (p.StartsWith('\\'))
+                if (p.StartsWith("\\"))
                 {
                     p = p.Substring(1);
                 }
diff --git a/src/SharpCompress/Common/Tar/Headers/TarHeader.cs b/src/SharpCompress/Common/Tar/Headers/TarHeader.cs
index c961fe52d..08f567ed8 100644
--- a/src/SharpCompress/Common/Tar/Headers/TarHeader.cs
+++ b/src/SharpCompress/Common/Tar/Headers/TarHeader.cs
@@ -196,7 +196,7 @@ private static void WriteStringBytes(ReadOnlySpan<byte> name, Span<byte> buffer,
         {
             name.CopyTo(buffer);
             int i = Math.Min(length, name.Length);
-            buffer.Slice(i, length - i).Fill(0);
+            buffer.Slice(i, length - i).Clear();
         }
 
         private static void WriteStringBytes(string name, byte[] buffer, int offset, int length)
diff --git a/src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs b/src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs
index 6068d610a..241479d5e 100644
--- a/src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs
+++ b/src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs
@@ -18,7 +18,7 @@ internal bool IsDirectory
         {
             get
             {
-                if (Name.EndsWith('/'))
+                if (Name.EndsWith("/"))
                 {
                     return true;
                 }
@@ -26,7 +26,7 @@ internal bool IsDirectory
                 //.NET Framework 4.5 : System.IO.Compression::CreateFromDirectory() probably writes backslashes to headers
                 return CompressedSize == 0
                        && UncompressedSize == 0
-                       && Name.EndsWith('\\');
+                       && Name.EndsWith("\\");
             }
         }
 
diff --git a/src/SharpCompress/Compressors/Deflate/GZipStream.cs b/src/SharpCompress/Compressors/Deflate/GZipStream.cs
index e5572576a..ce126bc5b 100644
--- a/src/SharpCompress/Compressors/Deflate/GZipStream.cs
+++ b/src/SharpCompress/Compressors/Deflate/GZipStream.cs
@@ -372,16 +372,16 @@ public string FileName
                 {
                     return;
                 }
-                if (_fileName.Contains('/'))
+                if (_fileName.Contains("/"))
                 {
                     _fileName = _fileName.Replace('/', '\\');
                 }
-                if (_fileName.EndsWith('\\'))
+                if (_fileName.EndsWith("\\"))
                 {
                     throw new InvalidOperationException("Illegal filename");
                 }
 
-                if (FileName.Contains('\\'))
+                if (FileName.Contains("\\"))
                 {
                     // trim any leading path
                     int length = _fileName.Length;
diff --git a/src/SharpCompress/Compressors/PPMd/H/ModelPPM.cs b/src/SharpCompress/Compressors/PPMd/H/ModelPPM.cs
index 001c69503..842502751 100644
--- a/src/SharpCompress/Compressors/PPMd/H/ModelPPM.cs
+++ b/src/SharpCompress/Compressors/PPMd/H/ModelPPM.cs
@@ -137,7 +137,7 @@ public ModelPpm()
 
         private void RestartModelRare()
         {
-            new Span<int>(_charMask).Fill(0);
+            new Span<int>(_charMask).Clear();
             SubAlloc.InitSubAllocator();
             _initRl = -(_maxOrder < 12 ? _maxOrder : 12) - 1;
             int addr = SubAlloc.AllocContext();
@@ -228,7 +228,7 @@ private void StartModelRare(int maxOrder)
         private void ClearMask()
         {
             _escCount = 1;
-            new Span<int>(_charMask).Fill(0);
+            new Span<int>(_charMask).Clear();
         }
 
         internal bool DecodeInit(IRarUnpack unpackRead, int escChar)
diff --git a/src/SharpCompress/Compressors/PPMd/H/SubAllocator.cs b/src/SharpCompress/Compressors/PPMd/H/SubAllocator.cs
index 38a1ca2c0..5c4ca30db 100644
--- a/src/SharpCompress/Compressors/PPMd/H/SubAllocator.cs
+++ b/src/SharpCompress/Compressors/PPMd/H/SubAllocator.cs
@@ -360,7 +360,7 @@ public virtual void DecPText(int dPText)
         public virtual void InitSubAllocator()
         {
             int i, k;
-            new Span<byte>(_heap, _freeListPos, SizeOfFreeList()).Fill(0);
+            new Span<byte>(_heap, _freeListPos, SizeOfFreeList()).Clear();
 
             _pText = _heapStart;
 
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack.cs b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack.cs
index ff522c4a1..4e1d74c77 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack.cs
@@ -729,13 +729,13 @@ private void UnpInitData(bool solid)
             if (!solid)
             {
                 tablesRead = false;
-                new Span<int>(oldDist).Fill(0); // memset(oldDist,0,sizeof(OldDist));
+                new Span<int>(oldDist).Clear(); // memset(oldDist,0,sizeof(OldDist));
 
                 oldDistPtr = 0;
                 lastDist = 0;
                 lastLength = 0;
 
-                new Span<byte>(unpOldTable).Fill(0); // memset(UnpOldTable,0,sizeof(UnpOldTable));
+                new Span<byte>(unpOldTable).Clear(); // memset(UnpOldTable,0,sizeof(UnpOldTable));
 
                 unpPtr = 0;
                 wrPtr = 0;
@@ -837,7 +837,7 @@ private bool ReadTables()
 
             if ((bitField & 0x4000) == 0)
             {
-                new Span<byte>(unpOldTable).Fill(0); // memset(UnpOldTable,0,sizeof(UnpOldTable));
+                new Span<byte>(unpOldTable).Clear(); // memset(UnpOldTable,0,sizeof(UnpOldTable));
             }
             AddBits(2);
 
@@ -1109,7 +1109,7 @@ private bool AddVMCode(int firstByte, List<byte> vmCode, int length)
             oldFilterLengths[FiltPos] = StackFilter.BlockLength;
 
             // memset(StackFilter->Prg.InitR,0,sizeof(StackFilter->Prg.InitR));
-            new Span<int>(StackFilter.Program.InitR).Fill(0);
+            new Span<int>(StackFilter.Program.InitR).Clear();
             StackFilter.Program.InitR[3] = RarVM.VM_GLOBALMEMADDR; // StackFilter->Prg.InitR[3]=VM_GLOBALMEMADDR;
             StackFilter.Program.InitR[4] = StackFilter.BlockLength;
 
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack15.cs b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack15.cs
index 52144c209..435a6fcae 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack15.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack15.cs
@@ -652,9 +652,9 @@ private void initHuff()
                 ChSetC[I] = ((~I + 1) & 0xff) << 8;
             }
 
-            new Span<int>(NToPl).Fill(0); // memset(NToPl,0,sizeof(NToPl));
-            new Span<int>(NToPlB).Fill(0); // memset(NToPlB,0,sizeof(NToPlB));
-            new Span<int>(NToPlC).Fill(0); // memset(NToPlC,0,sizeof(NToPlC));
+            new Span<int>(NToPl).Clear(); // memset(NToPl,0,sizeof(NToPl));
+            new Span<int>(NToPlB).Clear(); // memset(NToPlB,0,sizeof(NToPlB));
+            new Span<int>(NToPlC).Clear(); // memset(NToPlC,0,sizeof(NToPlC));
             corrHuff(ChSetB, NToPlB);
         }
 
@@ -670,7 +670,7 @@ private void corrHuff(int[] CharSet, int[] NumToPlace)
                     // & ~0xff) | I;
                 }
             }
-            new Span<int>(NumToPlace).Fill(0); // memset(NumToPlace,0,sizeof(NToPl));
+            new Span<int>(NumToPlace).Clear(); // memset(NumToPlace,0,sizeof(NToPl));
             for (I = 6; I >= 0; I--)
             {
                 NumToPlace[I] = (7 - I) * 32;
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack20.cs b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack20.cs
index 94440890e..ad022c6bf 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack20.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV1/Unpack20.cs
@@ -263,7 +263,7 @@ private bool ReadTables20()
             if (0 == (BitField & 0x4000))
             {
                 // memset(UnpOldTable20,0,sizeof(UnpOldTable20));
-                new Span<byte>(UnpOldTable20).Fill(0);
+                new Span<byte>(UnpOldTable20).Clear();
             }
             AddBits(2);
 
@@ -371,7 +371,7 @@ private void unpInitData20(bool Solid)
                 AudV[3] = new AudioVariables();
 
                 // memset(UnpOldTable20,0,sizeof(UnpOldTable20));
-                new Span<byte>(UnpOldTable20).Fill(0);
+                new Span<byte>(UnpOldTable20).Clear();
             }
         }
 
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackUtility.cs b/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackUtility.cs
index 11fa777df..9559e9b48 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackUtility.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV1/UnpackUtility.cs
@@ -187,7 +187,7 @@ internal static void makeDecodeTables(byte[] lenTab, int offset, Decode.Decode d
             int i;
             long M, N;
 
-            new Span<int>(dec.DecodeNum).Fill(0); // memset(Dec->DecodeNum,0,Size*sizeof(*Dec->DecodeNum));
+            new Span<int>(dec.DecodeNum).Clear(); // memset(Dec->DecodeNum,0,Size*sizeof(*Dec->DecodeNum));
 
             for (i = 0; i < size; i++)
             {
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack15_cpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack15_cpp.cs
index 44f2f5acc..fbcb55f10 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack15_cpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack15_cpp.cs
@@ -546,9 +546,9 @@ private void InitHuff()
     ChSetA[I]=(ushort)I;
     ChSetC[I]=(ushort)(((~I+1) & 0xff)<<8);
   }
-  new Span<byte>(NToPl).Fill(0);
-  new Span<byte>(NToPlB).Fill(0);
-  new Span<byte>(NToPlC).Fill(0);
+  new Span<byte>(NToPl).Clear();
+  new Span<byte>(NToPlB).Clear();
+  new Span<byte>(NToPlC).Clear();
   CorrHuff(ChSetB,NToPlB);
 }
 
@@ -558,7 +558,7 @@ private void CorrHuff(ushort[] CharSet,byte[] NumToPlace)
   for (I=7;I>=0;I--)
     for (J=0;J<32;J++)
       CharSet[J]=(ushort)((CharSet[J] & ~0xff) | I);
-  new Span<byte>(NumToPlace, 0, NToPl.Length).Fill(0);
+  new Span<byte>(NumToPlace, 0, NToPl.Length).Clear();
   for (I=6;I>=0;I--)
     NumToPlace[I]=(byte)((7-I)*32);
 }
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack20_cpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack20_cpp.cs
index c1400d9a1..05972f18f 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack20_cpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack20_cpp.cs
@@ -231,7 +231,7 @@ private bool ReadTables20()
 
   if ((BitField & 0x4000) != 0)
   {
-    new Span<byte>(UnpOldTable20).Fill(0);
+    new Span<byte>(UnpOldTable20).Clear();
   }
 
   Inp.addbits(2);
@@ -363,7 +363,7 @@ private void UnpInitData20(bool Solid)
 
     //memset(AudV,0,sizeof(AudV));
     AudV = new AudioVariables[4];
-    new Span<byte>(UnpOldTable20).Fill(0);
+    new Span<byte>(UnpOldTable20).Clear();
     //memset(MD,0,sizeof(MD));
     MD = new DecodeTable[4];
   }
diff --git a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
index 1add29720..549ca5d90 100644
--- a/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
+++ b/src/SharpCompress/Compressors/Rar/UnpackV2017/Unpack.unpack_cpp.cs
@@ -220,7 +220,7 @@ private void UnpInitData(bool Solid)
 {
   if (!Solid)
   {
-    new Span<uint>(OldDist).Fill(0);
+    new Span<uint>(OldDist).Clear();
     OldDistPtr=0;
     LastDist=LastLength=0;
 //    memset(Window,0,MaxWinSize);
@@ -270,7 +270,7 @@ private void MakeDecodeTables(byte[] LengthTable, int offset, DecodeTable Dec,ui
 
   // Set the entire DecodeNum to zero.
   //memset(Dec->DecodeNum,0,Size*sizeof(*Dec->DecodeNum));
-  new Span<ushort>(Dec.DecodeNum).Fill(0);
+  new Span<ushort>(Dec.DecodeNum).Clear();
 
   // Initialize not really used entry for zero length code.
   Dec.DecodePos[0]=0;
diff --git a/src/SharpCompress/Crypto/RijndaelEngine.cs b/src/SharpCompress/Crypto/RijndaelEngine.cs
index cb105d513..654d45567 100644
--- a/src/SharpCompress/Crypto/RijndaelEngine.cs
+++ b/src/SharpCompress/Crypto/RijndaelEngine.cs
@@ -81,7 +81,7 @@ public class RijndaelEngine
             57, 75, 221, 124, 132, 151, 162, 253, 28, 36, 108, 180, 199, 82, 246, 1
         };
 
-        private static ReadOnlySpan<byte> S => new byte[]
+        private static readonly byte[] S =
         {
             99, 124, 119, 123, 242, 107, 111, 197, 48, 1, 103, 43, 254, 215, 171, 118,
             202, 130, 201, 125, 250, 89, 71, 240, 173, 212, 162, 175, 156, 164, 114, 192,
@@ -101,7 +101,7 @@ public class RijndaelEngine
             140, 161, 137, 13, 191, 230, 66, 104, 65, 153, 45, 15, 176, 84, 187, 22
         };
 
-        private static ReadOnlySpan<byte> Si => new byte[]
+        private static readonly byte[] Si =
         {
             82, 9, 106, 213, 48, 54, 165, 56, 191, 64, 163, 158, 129, 243, 215, 251,
             124, 227, 57, 130, 155, 47, 255, 135, 52, 142, 67, 68, 196, 222, 233, 203,