First draft of rule language formalisation.

README.md

@@ -1,8 +1,8 @@
 # Data Quality Committee Rules & Guidance
 
-The following automated checks have been drawn from experience with IFRS filings to the SEC and form the initial XBRL International Data Quality Rules in the Beta Release. To review human-readable versions of the validations in this release, click any of the files linked in the "Number" column below. 
+The following automated checks have been drawn from experience with IFRS filings to the SEC and form the initial XBRL International Data Quality Rules in the Beta Release. 
 
-These freely-available automated checks are written in an [open-source processing language (XULE)](https://xbrl.us/home/use/what-is-xule) that is used for XBRL business rules, rendering, and data collection activities. The open source [XULE engine and ESEF plugin](https://github.com/xbrlus/xule/releases/latest) works with the [Arelle](https://arelle.org/pub) processor, and works with the ruleset.zip files maintained here on ESEF filings. 
+The specification of the current ESEF DQR rules can be found below:
 
 | Number | Short name | Rule version |
 | ----- | ----- | ----- |
@@ -25,6 +25,28 @@ These freely-available automated checks are written in an [open-source processin
 | [DQC_IFRS_0130](docs/DQC_IFRS_0130/DQC_0130.md) | Earnings Per Share Calculation | 17 |
 | [DQC_IFRS_0138](docs/DQC_IFRS_0138/DQC_0138.md) | Missing Abstract from Financial Statements | 17 |
 
+## Documentation definitions
+
+The rules definitions make reference to the following terms:
+
+* The **report taxonomy** is the DTS of XBRL Report, and includes the extension taxonomy.
+* THe **base taxonomy** is the IFRS taxonomy corresponding to the ruleset version.  The entry point used for each ruleset is shown below.
+
+## IFRS Entry Points
+
+The following entry points define the _base taxonomy_ for each version of the ruleset:
+
+| Version | Entry point |
+| ------- | ----------- |
+| ESEF DQR 2019 | `http://xbrl.ifrs.org/taxonomy/2019-03-27/full_ifrs_entry_point_2019-03-27.xsd` |
+| ESEF DQR 2020 | `http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs_entry_point_2020-03-16.xsd` | 
+| ESEF DQR 2021 | `http://xbrl.ifrs.org/taxonomy/2021-03-24/full_ifrs_entry_point_2021-03-24.xsd` | 
+
+## Reference implementation
+
+A reference implementation of the ESEF DQR rules is also available.  The reference implementation is defined using the [XULE language](https://xbrl.us/home/use/what-is-xule) developed by XBRL US.  The language is free to use, and an open source [XULE engine](https://github.com/xbrlus/xule/releases/latest) is available for the [Arelle](https://arelle.org/pub) XBRL processor.   
+
+
 © Copyright 2015 - 2022 XBRL US, Inc. All rights reserved.   
 See [License](https://xbrl.us/dqc-license) for license information.  
 See [Patent Notice](https://xbrl.us/dqc-patent) for patent infringement notice.  

docs/DQC_IFRS_0008/DQC_0008.md

@@ -1,7 +1,7 @@
 # Reversed Calculation
 Rule ID: DQC_0008   
 
-## Rule function
+## Rule description
 
 This rule evaluates whether a calculation relationship in the company's extension is a reversal of the calculation defined in the base taxonomy used for the filing. The rule checks if the element representing the calculation total and the element representing the component are a reversal of those same elements defined in the base taxonomy with the same calculation weight.  
 
@@ -13,6 +13,10 @@ Users expect that the calculation relationships defined between elements in the
 
 However, if the company changed the calculation relationship so that Property Plant and Equipment was a component of Mining Assets then a user of the data will have a different meaning of the concept of that reported by the preparer.  
 
+## Rule specification
+
+For each `summation-item` relationship defined in the _report taxonomy_ from a source concept **S** to a target concept **T** with calculation weight **W** there MUST NOT exist a `summation-item` relationship in the _base taxonomy_ with a source concept of **T** and a calculation weight of **W**.
+
 ## Example rule message 
 (Note: Presentation style of rule messages may differ among software implementations of the rules.)