What is the expectation for <last-modified> in <metadata>?

[telosBA]

• This is a ...

  • [ ] concern - I think something needs to be different.
  • [x] question - I didn't understand something.
  • [ ] kudos - I found something helpful and want to encourage it in future FedRAMP publications.
  • [ ] request - I would like to see something additional provided.

• This relates to ...

  • [ ] the FedRAMP OSCAL Registry (Excel File)
  • [ ] the Guide to OSCAL-based FedRAMP Content (PDF)
  • [x] the Guide to OSCAL-based FedRAMP System Security Plans (SSP) (PDF)
  • [ ] the Guide to OSCAL-based FedRAMP Security Assessment Plans (SAP) (PDF)
  • [ ] the Guide to OSCAL-based FedRAMP Security Assessment Reports (SAR) (PDF)
  • [ ] the Guide to OSCAL-based FedRAMP Plan of Action and Milestones (POA&M) (PDF)
  • [x] the FedRAMP SSP OSCAL Template (JSON or XML Format)
  • [ ] the FedRAMP SAP OSCAL Template (JSON or XML Format)
  • [ ] the FedRAMP SAR OSCAL Template (JSON or XML Format)
  • [ ] the FedRAMP POA&M OSCAL Template (JSON or XML Format)
  • [ ] General/Overall
  • [ ] Other

NOTE: For feedback related to the OSCAL syntax itself, please create or add to an issue in the NIST OSCAL Repository.

• Where, exactly?
  • For the registry, please indicate the tab and cell, or other clear identifier
  • For the guide, please indicate the section number and printed page number (lower right corner)
  • For the OSCAL XML or JSON files, please indicate XML or JSON; and indicate the line number, field id, or other clear location identifier

FedRAMP-SSP-OSCAL-Template.xml Line 9

• What is your feedback?

• What version of OSCAL are you using? (Check our info on supported OSCAL versions) 1.0.2

• What action would you like to see from the FedRAMP PMO?

What is the definition of <last-modified> found under <metadata> i.e. what value that should populate this tag? Will the "Last Published" date suffice?

• Other information (e.g. detailed explanation, related issues, suggestions how to fix, links for us to have context, eg. slack, gitter, etc)

[david-waltermire]

According to the OSCAL documentation this is the "date and time the document was last modified. The date-time value must be formatted according to RFC 3339 with full time and time zone included."

The remarks provide some additional guidance that is important here that should help you answer your question.