eCTD module structure and naming

Concept2Cure holds the truth about a sequence; this skill tells you how to ask it and how to read the answer. Never assert that a structure is valid, a section is present, or a document is filed unless a connector tool said so.

The five modules (ICH M4)

Module	Content	Regional?
1	Administrative information and prescribing information (cover letter, forms, labeling, environmental assessment, …)	Yes — FDA m1/us, EU m1/eu
2	Summaries: 2.2 Introduction, 2.3 QOS, 2.4 Nonclinical overview, 2.5 Clinical overview, 2.6 Nonclinical summaries, 2.7 Clinical summaries	No
3	Quality: 3.2.S drug substance, 3.2.P drug product, 3.2.A appendices, 3.2.R regional, 3.3 literature	No (3.2.R regional)
4	Nonclinical study reports (4.2.1 pharmacology, 4.2.2 PK, 4.2.3 toxicology), 4.3 literature	No
5	Clinical study reports (5.3.1 biopharmaceutic, 5.3.3 PK, 5.3.4 PD, 5.3.5 efficacy/safety by indication, 5.3.6 post-marketing), 5.4 literature	No

A section code names a place a document can go: 1.2, 2.5, 2.7.3, 3.2.S.4.2, 5.3.5.1. A bare module (3) is a container, never a leaf; the connector refuses it.

Naming rules the validators enforce

• Files and folders: lowercase letters, digits, hyphen, underscore, dot; no spaces; PDF leaves; keep paths short and stable across sequences.
• Sequence numbers are four digits (0000, 0001, …); lifecycle operators are new, replace, append, delete and a replace/append must reference the leaf it modifies in the prior sequence.
• Every leaf carries an MD5 checksum in util/index-md5.txt; empty files are rejected by FDA.
• Regional backbone: us-regional.xml (FDA), eu-regional.xml (EMA), jp-regional.xml (PMDA), beside the ICH index.xml.

Workflow with the connector

1. Find the sequence: c2c_list_submissions → c2c_list_sequences → c2c_get_sequence_status (shows existing leaves and the release-signature state).
2. Check the proposed structure before filing: c2c_validate_ectd_structure with sequence_id (stored leaves) or an explicit leaves[]. Report the engine's valid, score, missing required sections and the external validator posture verbatim. Passing the built-in check is not passing the agency validator; say so when externalValidator.configured is false.
3. File the draft: c2c_file_draft_for_review with sequence_id, section_code, title, a document pointer (vault_document_id from c2c_list_vault_documents, or document_table + document_id) and a reason. It creates a DRAFT leaf and returns the Submission Center link. Tell the user a named person must review, freeze and sign there; you cannot.
4. Re-validate after filing with c2c_validate_ectd_structure (sequence_id) and report the delta.

What to do with refusals

A refusal names its cause: the sequence is frozen or dispatched, the document belongs to another organisation, the section code is not a CTD section, the scope was not granted. Relay it; do not retry with a different section or document to "make it work".