A subdocument target can change without changing Word text

A Word master document can keep all stored text, its w:subDoc anchor, and its
relationship ID fixed while changing which separate subdocument it names. A text
diff cannot make that dependency retarget visible, but a static reviewer can
record it without opening or merging either document.

Document Change Assurance Benchmark 0.4.0
adds its fifteenth deterministic pair:
external.subdocument_target_retargeted. Both sides preserve every package
member, every w:t sequence, and a fixed w:subDoc r:id marker. Only
word/_rels/document.xml.rels changes, retargeting the standard external
subdocument relationship.

Inspect the dependency; do not open it

Microsoft’s Open XML documentation for SubDocumentReference
defines w:subDoc as an anchor for a subdocument location. Its corresponding
OOXML relationship is an external master-document dependency. DCAB records that
stored relationship boundary only: its builder, validator, scorer, and adapter
never retrieve a target, launch Word, or merge subdocument content.

All package targets are synthetic example.invalid values. The public truth
declares only external_document_dependency_target_changed with the
subdocument dependency subtype. It excludes targets, relationship IDs,
relationship paths, and subdocument content.

A deterministic package boundary

The generator renders the anchor directly in the main document body and keeps a
standard external subDocument relationship. An independent verifier checks
those requirements, deterministic package bytes, stable package members,
unchanged stored text, and the exact one-member pair boundary. The standard
python-docx reader opens all 28 .docx fixtures, and its lower-level OPC
reader opens all 30 packages.

The optional local DocFence 0.27.0
adapter maps public aggregate external-relationship and external-document-
dependency inventory evidence without consuming targets or private signatures.

DCAB 0.4.0 keeps fixture schema version 1 because the public envelopes are
unchanged; it extends the corpus from 14 to 15 cases. It does not claim that a
subdocument exists, is safe, will be loaded, or will render a particular way.

The source, generated corpus, and verifier are MIT-licensed on
GitHub. Read the
canonical release note
for the full boundary and install command.