Adding Custom "ident" Sources in shorthand XCCDFs

Hi all, as briefly mentioned already in yesterdays’ Contributor Workshop, our customer wants to enrich the SSG content by adding references to their internal security requirements. I wonder how I could add my own Security Identifiers, because when trying to simply add e.g. a „customerident“ attribute into the shorthand XCCDF as per below, my build fails with: [...] xmllint --format --output output/shorthand.xml output/shorthand.xml xsltproc --stringparam ssg_version "0.1.27" -o output/xccdf-unlinked-unresolved.xml transforms/shorthand2xccdf.xslt output/shorthand.xml oscap xccdf resolve -o output/xccdf-unlinked-empty-groups.xml output/xccdf-unlinked-unresolved.xml File 'output/xccdf-unlinked-unresolved.xml' line 153: Element '{http://checklists.nist.gov/xccdf/1.1}ident': The attribute 'system' is required but missing. File 'output/xccdf-unlinked-unresolved.xml' line 167: Element '{http://checklists.nist.gov/xccdf/1.1}ident': The attribute 'system' is required but missing. File 'output/xccdf-unlinked-unresolved.xml' line 182: Element '{http://checklists.nist.gov/xccdf/1.1}ident': The attribute 'system' is required but missing. File 'output/xccdf-unlinked-unresolved.xml' line 190: Element '{http://checklists.nist.gov/xccdf/1.1}ident': The attribute 'system' is required but missing. Invalid XCCDF Checklist content(1.1) in output/xccdf-unlinked-unresolved.xml. ../../shared/product-make.include:60: recipe for target 'output/xccdf-unlinked-empty-groups.xml' failed make: *** [output/xccdf-unlinked-empty-groups.xml] Error 1 Do I have to „register“/„declare“ the new identifier type, and if so where and how? Example of what I'm trying to achieve: <Rule id="sshd_allow_only_protocol2"> <title>My Title</title> <description>My description</description> <rationale>My rationale</rationale> <ident cce="27072-8" customerident="1234" stig="RHEL-06-000227"/> <oval id="sshd_allow_only_protocol2"/> <ref disa="776,774,1436" nist="AC-3(10),IA-5(1)(c)"/> </Rule> Any pointers highly appreciated :-) ! Thanks & regards Oliver