Manual:Parameters to Special:Upload/gu
The parameters to Special:Upload are:
wpSourceType
wpUpload
wpUploadIgnoreWarning
wpDestFile
wpUploadFile
wpLicense
wpDestFileWarningAck
wpIgnoreWarning
wpWatchthis
wpUploadCopyStatus
wpUploadSource
wpForReUpload
wpUploadDescription
wpCancelUpload
wpReUpload
andwpEditToken