procedure CopyTIdLongWord(
    const ASource: LongWord; 
    var VDest: TIdBytes; 
    const ADestIndex: Integer
);

CopyTIdLongWord is a procedure used to copy bytes values from the specified LongWord data type into the array of bytes indicated by VDest. 

ASource identifies the ordinal data type with byte values to be copied. 

VDest is the array bytes where byte values from the ordinal data type will be stored. 

ADestIndex indicates the initial position in the array of bytes to store copied byte values. ADestIndex is a zero-based offset into the array of bytes. 

On the .Net platform, CopyTIdLongWord calls the GetBytes method in the FCL System.BitConverter class to retrieve the byte values for the ordinal data type in ASource. The Copy method from the FCL System.Array class is called to perform the copy operation using the destination storage and index. 

For all other platforms where the Borland RTL is implemented, the Move procedure from SysUtils.pas is called to copy values from ASource into VDest at the indicated position using the native size of the ordinal data type.