Formula Specification Public Working Draft Overview
Public Working Draft dated 2007-12-31
This document:
	XBRL-Formulas-Overview-PWD-2007-12-31.rtf
is non-normative.
Editors
Geoff Shuetrim	geoff@galexy.net	Galexy Pty. Limited	
Abstract
This document explains the various materials issued as a part of the public working draft released by the Formula Working Group (FWG).
Status
Circulation of this Public Working Draft is unrestricted.  Recipients of this draft are invited to submit comments to Geoff Shuetrim, and to submit notification of any relevant patent rights of which they are aware and to provide supporting documentation.
Table of Contents
Formula Specification Public Working Draft Overview	
Public Working Draft dated 2007-07-13	
1	Introduction	
2	Requirements	
3	Specifications	
4	Schemas	
5	Examples	
6	Conformance suite tests	
7	Focus issues	
7.1	Custom function signatures	
7.2	Implicit filtering	
7.3	Implied XPath expressions	
7.4	Explicit filters	
7.5	Normative schemas	
A.	References (non-normative)	
B.	Intellectual Property Status (non-normative)	
C.	Document History (non-normative)	
D.	Approval process (non‑normative)	

1	Introduction
This document provides an overview of this Public Working Draft (PWD).  It describes the various materials included in the PWD by the Formula Working Group (FWG).  It also lists a series of issues about which the FWG hope to receive specific feedback to drive the next steps of the specification development process.
The PWD includes:
•	the requirements agreed by the FWG;
•	specifications for various components of the formula specification; and
•	normative schemas for the specifications.
2	Requirements
The requirements agreed upon by the FWG are included in the PWD.  There is a document for formula requirements and a document for XBRL instance validation requirements. These requirements are accompanied by motivating examples.
3	Specifications
The formula specification has been modularised, resulting in a large number of specification documents.
The specifications in this PWD are:
●	Validation
●	Consistency assertions
●	Value assertions
●	Existence assertions
●	Formulae
●	Variables
●	Various filters
●	Generic labels
●	Generic references
These specifications depend on the public working draft of the generic link specification.
Some individuals may find it easier to read the variable specification first, followed by some or all of the the filter specifications.  The formula specification and the assertion specifications may then be more easily understood.
Being a PWD, these specifications may continue to evolve.  In particular, many of the XBRL functions referred to by the filter specifications have not yet been defined in a function specification or in the function registry.
Also note that the specifications in this PWD only address the XBRL report validation usage pattern.  Other specialised usage patterns for formulae will be addressed in extension specifications after the formula specification has reached candidate recommendation status.  Among these usage patterns, priority will be given to tuple creation, and formula chaining.
4	Schemas
A range of XML documents are also included in the PWD.  These can be found in the  directory in the ZIP file containing the PWD.
The xml directory contains a directory called .  This directory contains the schemas that support the specifications in the PWD.  Each specification names the schemas that support it.  The names of the files in the  directory correspond to these schema names.
A schema for the generic links is included in this distribution.  This will not be released as part of any candidate recommendation.  Instead, normative schemas will reference the normative version of the schema for generic link constructs.
5	Conformance suite tests
A conformance suite is currently under development.  This contains a broad range of examples illustrating usage of the specifications.  Those with access to the FWG CVS repository will be able to explore the latest versions of the test cases.
6	Focus issues
Almost all of the feedback on the second PWD has been incorporated into this third PWD.
This third PWD also includes a range of significant variations on the second PWD, largely reflecting refinement of the implicit filtering mechanism.  It also includes a comprehensive set of non-normative examples, a clearly distinguished set of terminology definitions and a set of error codes.  The normative schemas supporting the specifications have also been substantially refined.
Unlike previous PWDs, there are no specific focus issues for this PWD.  That said, feedback remains welcome on all aspects of the specifications.
A.	Intellectual Property Status (non-normative)
This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works.  However, this document itself may not be modified in any way, such as by removing the copyright notice or references to XBRL International or XBRL organizations, except as required to translate it into languages other than English.  Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).
This document and the information contained herein is provided on an "AS IS" basis and XBRL INTERNATIONAL DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
The attention of users of this document is directed to the possibility that compliance with or adoption of XBRL International specifications may require use of an invention covered by patent rights. XBRL International shall not be responsible for identifying patents for which a license may be required by any XBRL International specification, or for conducting legal inquiries into the legal validity or scope of those patents that are brought to its attention. XBRL International specifications are prospective and advisory only. Prospective users are responsible for protecting themselves against liability for infringement of patents.  XBRL International takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights.  Members of XBRL International agree to grant certain licenses under the XBRL International Intellectual Property Policy (www.xbrl.org/legal).
B.	Document History (non-normative)
Date	Editor	Summary	
2007-12-27	Geoff Shuetrim	First draft.	

C.	Approval process (non‑normative)
This document will not be released as a part of any final recommendation.