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+# pdftract-2a6rk: OCG /OCProperties parsing verification
+
+## Summary
+
+The OCG (Optional Content Groups) implementation is complete in `/home/coding/pdftract/crates/pdftract-core/src/parser/ocg.rs`. The implementation was already present in the codebase when this task was picked up.
+
+## Implementation details
+
+### Public API
+- `parse_oc_properties(resolver: &XrefResolver, oc_props_ref: Option<ObjRef>) -> OcProperties`
+- Located in `crates/pdftract-core/src/parser/ocg.rs:273-422`
+
+### Data structures
+
+1. **OcProperties** (lines 192-271):
+   - `present: bool` — true if /OCProperties was present
+   - `groups: HashMap<ObjRef, OcGroup>` — all OCGs in the document
+   - `default_visibility: HashMap<ObjRef, bool>` — default visibility per OCG
+   - `base_state: BaseState` — overall default (ON/OFF/Unchanged)
+   - `ocmds: HashMap<ObjRef, Ocmd>` — optional content membership dicts
+   - `diagnostics: Vec<Diagnostic>` — parsing diagnostics
+
+2. **OcGroup** (lines 122-186):
+   - `name: Option<String>` — /Name entry
+   - `intent: Vec<String>` — /Intent (e.g., "View", "Design")
+   - `usage: Option<PdfDict>` — /Usage dictionary
+
+3. **BaseState** enum (lines 15-49):
+   - `On`, `Off`, `Unchanged`
+   - `Unchanged` treated as `On` for default config
+
+4. **Ocmd** and **OcmdPolicy** (lines 51-120):
+   - OCMD support for boolean combinations (AllOn, AnyOn, AllOff, AnyOff)
+   - Policy evaluation deferred to Phase 3
+
+### Catalog integration
+
+The catalog.rs already integrates OCG parsing:
+- Lines 486-491: Extract /OCProperties from catalog
+- Stores result in `Catalog.oc_properties: Option<OcProperties>`
+
+## Acceptance criteria verification
+
+| Criteria | Status | Test |
+|----------|--------|------|
+| EC-16: OCG with default OFF state | ✅ PASS | `test_parse_oc_properties_base_state_off` |
+| /BaseState OFF + /ON [ocg1 ocg2] | ✅ PASS | `test_parse_oc_properties_with_on_array` |
+| No /OCProperties: present = false | ✅ PASS | `test_oc_properties_not_present` |
+| /OCMD with /AllOn policy preserved | ✅ PASS | `test_ocmd_parse`, `test_ocmd_evaluation_all_on` |
+| proptest: never panics on random input | ✅ PASS | `fuzz_parse_oc_properties_no_panics`, `fuzz_ocg_group_parse_no_panics`, `fuzz_ocmd_parse_no_panics` |
+| INV-8: no panics on arbitrary input | ✅ PASS | All proptests verify INV-8 compliance |
+
+## Test results
+
+```
+running 20 tests
+test parser::ocg::tests::test_base_state_from_name ... ok
+test parser::ocg::tests::test_ocmd_evaluation_any_on ... ok
+test parser::ocg::tests::test_ocmd_policy_from_name ... ok
+test parser::ocg::tests::test_ocg_group_parse ... ok
+test parser::ocg::tests::test_ocg_name_none ... ok
+test parser::ocg::tests::test_ocmd_parse ... ok
+test parser::ocg::tests::test_ocmd_parse_single_ref ... ok
+test parser::ocg::tests::test_parse_oc_properties_base_state_off ... ok
+test parser::ocg::tests::test_parse_oc_properties_off_overrides_on ... ok
+test parser::ocg::tests::test_parse_oc_properties_simple ... ok
+test parser::ocg::tests::test_ocg_name_retrieval ... ok
+test parser::ocg::tests::test_ocmd_evaluation_all_on ... ok
+test parser::ocg::tests::test_parse_oc_properties_with_off_array ... ok
+test parser::ocg::tests::test_parse_oc_properties_with_on_array ... ok
+test parser::ocg::tests::test_unknown_ocg_treated_as_visible ... ok
+test parser::ocg::tests::test_oc_properties_not_present ... ok
+test parser::ocg::tests::test_base_state_as_bool ... ok
+test parser::ocg::tests::proptests::fuzz_ocmd_parse_no_panics ... ok
+test parser::ocg::tests::proptests::fuzz_parse_oc_properties_no_panics ... ok
+test parser::ocg::tests::proptests::fuzz_ocg_group_parse_no_panics ... ok
+
+test result: ok. 20 passed; 0 failed; 0 ignored
+```
+
+## Phase 3 integration
+
+The `OcProperties` struct provides:
+- `is_visible(ocg_ref: ObjRef) -> bool` — check OCG default visibility
+- `is_ocmd_visible(ocmd_ref: ObjRef) -> bool` — evaluate OCMD policy
+- `ocg_name(ocg_ref: ObjRef) -> Option<&str>` — get OCG name
+
+Phase 3 content stream processing will use these methods to suppress glyphs inside `/OC /OCGRef` BDC blocks when the referenced OCG is OFF.
+
+## Files
+
+- Implementation: `crates/pdftract-core/src/parser/ocg.rs` (909 lines)
+- Catalog integration: `crates/pdftract-core/src/parser/catalog.rs` (lines 10, 326, 486-491)
+- Tests: inline in `ocg.rs` (lines 424-908)
+
+## Retrospective
+
+- **What worked:** The implementation was already complete and well-tested
+- **What didn't:** N/A (implementation was already present)
+- **Surprise:** The bead description matched an existing implementation exactly
+- **Reusable pattern:** Use `OcProperties::not_present()` for documents without /OCProperties