HtmlGlobals.Pas (ThtChar)
HtmlBuffer.pas (TBuffChar)
Depending on the compiler switch UNICODE ThtChar is set to an available unicode character type.
If UNICODE is defined it is set to Char otherwize to WideChar.
Type ThtChar is the character type used in HtmlViewer code.
Type TBuffChar is an alias for ThtChar and is used in HtmlBuffer.pas.