Xceed zip extra fields

Xceed zip extra fields

I'm looking for definitions and samples of the two Xceed extra field definitions that are mentioned in the zip file APPNOTE

Below are the entries in question
4.6 Third Party Mappings
   4.6.1 Third party mappings commonly used are:

          0x4f4c        Xceed original location extra field
          0x554e        Xceed unicode extra field
I've found a few examples of the Unicode field, and have reverse-engineered how it is structured, but I cannot find an example  for the "Xceed original location" field.

Anyone know where the official definitions for these fields live at and where I can get sample files ?

My interest in this is for a program, called zipdetails, that I'm writing that dumps details of zip file metadata.