I have reviewed usages of Encoding (most commonly Encoding.UTF8), and determined that most usages do not need to be changed. The following cases do not result in a BOM being generated:

• Encoding.UTF8.GetBytes(string)
• J2N.Text.StringExtensions.GetBytes(this string, Encoding)
• Use of Encoding.Default or Encoding.GetEncoding(0) which uses a BOM-less UTF8 encoding on modern .NET, or the system current code page on .NET Framework

The following cases ignore a BOM if present, and do not fail if there is not a BOM, and thus do not need to be changed to a BOM-less Encoding:

• Any TextReader use (such as StreamReader)
• IOUtils.GetDecodingReader(...)
• Encoding.UTF8.GetString(byte[])
• FileStream with FileAccess.Read

So you'll see in the PR that the amount of changes to address BOM issues are not very many; that's because most fall into those buckets above.