Improve copilot-instructions

- don't duplicate PR summary
- review concept organization/hierarchy

Author: dalito

.github/copilot-instructions.md

@@ -37,7 +37,8 @@ Let me know if you need help identifying the appropriate parent concepts!
 
 ### PR Review Style (Concise, no diff rehash)
 
-- Summarize changes in plain language: what changed and why.
+- Do summarize changes in plain language: what changed and why.
+- Do not summarise changes if the starting message of the PR already contains a summary.
 - Do not restate or quote diffs, hunks, or line-by-line changes.
 - Do not link to individual file diffs; reference files only when necessary (path + short purpose).
 - Focus feedback on correctness, classification, scope, and follow-ups rather than code excerpts.
@@ -74,6 +75,18 @@ Use simple heuristics based on PR intent and CI signals:
 2. **No direct .ttl edits**: Turtle files should only be modified by CI
 3. **Documentation**: Changes should be described in PR description
 4. **Size**: Large contributions should be split into smaller PRs
+5. **Organizational guidelines conformance**: Check adherence to Voc4Cat guidelines (labels, British English, definitions, duplicate avoidance) and concept organization rules (IS-A only in hierarchy, attributes not placed under entities, generic attribute concepts preferred, collections used for HAS-A/context, no PART-OF modeling in `skos:broader`).
+
+### Organizational Guidelines Conformance (Detail)
+
+When reviewing, explicitly verify the PR aligns with internal vocabulary organization policies:
+
+- **Hierarchy purity**: `skos:broader` / `skos:narrower` express only IS-A; no PART-OF or HAS-A misuse (see `docs/docs_usage/organizing-concepts.md`).
+- **Attribute purity**: Avoid object-specific attribute proliferation (preferred generic attributes).
+- **Collections usage**: Contextual HAS-A groupings use `skos:Collection` rather than hierarchical placement.
+- **Guidelines adherence**: Preferred label form, British English spelling, noun/noun-phrase, singular/plural rules, avoidance of trademarked names, non-circular concise definitions (see `docs/docs_usage/guidelines.md`).
+
+If any of these are violated, add a short actionable note (e.g., "Hierarchy misuse – attribute concept placed under entity; move under appropriate attribute parent"). Keep blocking vs. follow-up issues distinct.
 
 ### Helpful Resources
 
@@ -126,9 +139,9 @@ Classification:
 Quality:
 - PrefLabel + definition present (EN) per concept
 - No direct .ttl edits; TTL generated by CI
-- Conformance to guidelines <https://github.com/nfdi4cat/voc4cat/blob/main/docs/docs_usage/guidelines.md>:
+- Conformance to guidelines <https://github.com/nfdi4cat/voc4cat/blob/main/docs/docs_usage/guidelines.md> and concept organization <https://github.com/nfdi4cat/voc4cat/blob/main/docs/docs_usage/organizing-concepts.md>:
   British English; noun/noun-phrase form; duplicates avoided; appropriate
-  hyphenation; no slashes; definitions concise and non-circular.
+  hyphenation; no slashes; definitions concise and non-circular; IS-A-only hierarchy; attributes not under entities; collections for contextual HAS-A.
 
 Suggestions (optional):
 - <brief, actionable improvements; keep it short>