Forms the content disposition in a boundary marker for multipart form data.

sContentDisposition = 'Content-Disposition: form-data; name="%s"';

sContentDisposition is a String constant that repesents a value used in the boundary marker for data fields when multipart form data is written to a stream. sContentDisposition is used with other constants, like sContentTypePlaceHolder and sFileNamePlaceHolder, to form the complete boundary marker.