function RemoveHeaderEntry(
    AHeader: string; 
    AEntry: string
): string;

string - Content of the message header after removing the named argument and its associated value.

RemoveHeaderEntry is a String function used to extract parameter arguments found RFC-complaint message headers. 

AHeader is the RFC-compliant message header to be affected by the operation. 

AEntry is the parameter argument to locate and remove from the message header. 

RemoveHeaderEntry performs a case-insensitive comparison to locate the header specified in AEntry within the header represented by AHeader. 

RemoveHeaderEntry will also remove any trailing ';' character that would remain as an artifact for the removed argument and value. 

RemoveHeaderEntry returns the content for the header after removing the named argument and its associated value. 

RemoveHeaderEntry is used when processing headers in mail and news message parts