ISO 19115-3 export and 'field definitions'

[RalphAnhold_USDAERS]

I am trying to draft ISO 19115-3 compliant metadata in ArcGIS Pro.  The interface provides good help with completing the forms (red x's) to ensure standard is met.  I complete the Resource-Fields section as guided, then save.  I export the record using the 19115-3 format setting.   

Upon reading the exported XML, I expect to see field definitions in the <mdb:contentInfo> section.  Even if I search for OBJECTID, I see no field definition.  

How do I get a complete export of the metadata that was drafted?  Is there a custom export translator?  Is there more detailed guidance?

[DanPatterson]

Does it disagree with the notes here?

Export metadata to a standard format—ArcGIS Pro | Documentation

or

Create ISO 19115 and ISO 19139 metadata—ArcGIS Pro | Documentation

which does state

ArcGIS metadata includes content that's not included in the ISO 19139 standard, such as thumbnails and descriptions of the fields in an attribute table; this content can't be included in an ISO 19139-format XML file.

[TorrinHultgren2]

To add to Dan's answer, fields are part of the ISO Feature Catalogue 19110 schema, which was spun off and for a long time could only be referenced as a separate standalone document, but not included in a geospatial metadata ISO 19115 record.  19115-3 addressed that by allowing a 19110 schema to be embedded in a 19115 document, but adoption of 19115-3 has been painfully slow by everyone, not just Esri. In an ArcGIS record, feature metadata is still captured and stored in FGDC CSDGM schema. At the bottom of this article, Esri indicates they're working on it and will include those elements in an exported 19115-3 doc someday:

https://pro.arcgis.com/en/pro-app/latest/help/metadata/create-iso-19115-1-and-iso-19115-3-metadata.h...

Note:

While it is possible to include information about the fields in an attribute table in an ISO 19115-3 metadata XML file, the exporter does not include this information in the exported file at this time. This information will be included in the exported XML file in a future release of ArcGIS Pro.