From the FDA ICH M2 web page:
The International Conference on Harmonization (ICH) -
Multi-disciplinary Group 2 (M2) Expert Working Group (EWG) was established to
facilitate international electronic communication by evaluating and
recommending, open and non-proprietary - to the extent possible - Electronic
Standards for the Transfer of Regulatory Information (ESTRI) that will meet the
requirements of the pharmaceutical companies and regulatory authorities.
The M2 EWG has provided valuable functionality to the
diverse international information exchange needs identified by the members of
the three ICH regions, Europe, Japan, and USA (and Canada as observer). The M2
EWG recommendations provide a well-defined approach for the evaluation and
recommendation of standards. The M2 tasks have led to the recommendation of
various open international standards that allow for the international
transmission of information regardless of the technical infrastructure.
From the ICH eCTD Version 2.0
"The ICH M4 Expert Working Group (EWG) has defined the
Common Technical Document (CTD). The ICH M2 EWG has defined, in the current
document, the specification for the Electronic Common Technical Document (eCTD).
The eCTD is defined as an interface for industry to Agency transfer of
regulatory information while at the same time taking into consideration the
facilitation of the creation, review, lifecycle management and archival of the
electronic submission. The eCTD specification lists the criteria that will make
an electronic submission technically valid. The focus of the specification is to
provide the ability to transfer the registration application electronically from
industry to a regulatory authority. Industry to industry and Agency to Agency
transfer is not addressed... The specification for the eCTD is based upon
content defined within the CTD issued by the ICH M4 EWG. The CTD describes the
organization of modules, sections and documents. The structure and level of
detail specified in the CTD has been used as the basis for defining the eCTD
structure and content but where appropriate, additional details have been
developed within the eCTD specification. The philosophy of the eCTD is to
utilize open standards. Open standards, including proprietary standards, which
through their widespread usage can be considered de facto standards, are deemed
to be appropriate in general..."
The XML DTD:
"The XML eCTD DTD (Document Type Definition) defines the overall structure of
the submission. The purpose of the XML backbone is two-fold: (1) to manage
meta-data for the entire submission and each document within the submission and
(2) to constitute a comprehensive table of contents and provide corresponding
navigation aids. Meta-data on submission level includes information about
submitting and receiving organization, manufacturer, publisher, ID and kind of
the submission, and related data items. Examples for meta-data on document level
are versioning information, language, descriptive information such as document
names, checksums, etc. Details are defined in appendix 6.
The XML eCTD DTD describes the hierarchical structure according to the CTD as
defined by the ICH M4 expert working group. It includes multiple hierarchical
levels depending on the specific module as defined in the CTD. The actual
submission can include more hierarchical levels below those defined in the CTD.
The XML eCTD instance covers the entire submission including all hierarchical
levels and includes references to each individual file.
The submission should
include a style sheet that supports presentation of the XML instance, navigation
according to the table of contents and provides access to all documents within
the submission. A standard style sheet is defined and provided by the ICH M2
EWG. Presentation and navigation via other style sheets on the receiving side
should be possible.
The XML eCTD DTD includes a reference for each document to the physical file
within the folder structure. The XML eCTD DTD includes attributes for
descriptive names of folders and documents. [from the version 2.0 spec]The XML instance of any submission should be created and validated according
to the XML eCTD DTD as defined in appendix 8.