md. I’ll also keep carrying the specific repository + license notice on every walkthrough page so each doc makes its licensing context explicit.

Dataset Card Template

Metadata

• Dataset name: <UKB/ABCD/etc>
• Source / accession: <URL or data agreement>
• License / DUA: <e.g., UKB Research Analysis Tool terms>
• Primary contact: <PI / analyst>
• Related YAML: kb/datasets/<id>.yaml

Access & Storage

• Paths to raw data (e.g., /secure/ukb/raw), processed derivatives, and sync locations.
• Encryption / PHI considerations; who has access.

Hugging Face / Shared Mirrors

• Dataset repo + subset names, record counts, checksum or snapshot tags.
• Notes on sync cadence between mirrors and secured copies.

Cohort Summary

Split	N subjects	Notes
Train	<N>	<filters>
Val	<N>
Test	<N>

Add stratification notes (sex balance, age range, sites).

Modality-Specific Schema

• Column lists per modality (genes, ROIs, clinical tables) with links back to docs/data/schemas.md.
• Required covariates + units.

Overlap & Pairing Logic

• How subjects overlap with other modalities (e.g., gene × sMRI intersection).
• Inclusion/exclusion rules, QC flags (motion, missing genes, etc.).

Genomics / Base-Pair Stats

• Total base pairs, mean/median sequence length, tokenizer context alignment details.

Preprocessing Pipelines

• Imaging: software versions, atlases, smoothing, censoring thresholds.
• Genetics: variant calling, phasing, annotation, gene list definition.
• Clinical: diagnosis coding, questionnaire scoring.

Available Features & Covariates

• Feature tables (e.g., FreeSurfer ROIs, FC z-maps, gene embeddings).
• Covariates recommended for residualization (age, sex, site, motion, PCs, SES).
• Missingness patterns and imputation strategy if required.

QC & Harmonization

• Thresholds (FD < 0.3 mm, min TR length).
• Site/scanner harmonization (e.g., ComBat) or reasons for not applying.
• Logs / reports location.

Notes & Risks

• Any data use restrictions (no redistribution, publication review).
• Confounds or biases to monitor (ancestry imbalance, site skew).
• Planned updates or reprocessing tasks.

References

• Link to cohort publications / documentation.
• Internal tickets or notebooks for preprocessing runs.

Linked Walkthroughs & External Repos

• Walkthrough pages that describe preprocessing.
• external_repos/* scripts or configs that produced the released tensors (commit/tag + entrypoint).