Object Attributes v2 (OAv2) share common concepts of vendor, tag and value with OAv1, but also introduce the new ones like subsection and scope. Attributes with common properties are grouped into subsections. All the attributes in a subsection share the same encoding, comprehension, and scope. A subsection starting with the vendor name is considered public. The value of an attribute may be a string or an integer depending on the encoding set on its subsection.
The file format used by OAv2 is documented in Build Attributes for the Arm 64-bit Architecture (AArch64), as AArch64 introduced it first.