The following functions for UDR described here are:

udrAddError

Adds an error description message to the UDR, which will be visible from the Error Correction System Inspector window or the Data Veracity browser, Error Code column. A UDR can have several error descriptions.

...

Decodes a bytearray into a list of UDRs, and returns an error message if the operation fails. To route the UDRs to a subsequent agent, loop through the resulting list routing each element individually.

string udrDecode
 ( string  decoderName , 
 list<drudr>  UDRlist , 
 bytearray  indata , 
 boolean  fullDecode  ) //Optional

...

list<drudr> myList = listCreate(drudr);

if (udrDecode("myFolder.myFormat.myDecoder", 
 myList, input) == null) {
 // Do something
} else {
 // Error handling
}

udrEncode

Encodes a UDR.

bytearray udrEncode
 ( string  encoderName ,
 drudr  myUDR  )

...