CommentLog080807-NDR30-PFR-IBM-Review comments - UNECE

CommentLog080807-NDR30-PFR-IBM-Review comments - UNECE UN/CEFACTS Core Components Version 3.0 Naming and Design Rules – Review Comments Patrick Rooney – IBM Corporation General Comments: - The NDR direction is very good, especially with the increased focus on simplicity I see in the documentation. The data modeling and design approach described by this NDR should help organizations move away from proprietary silo’d data solutions to an environment where data is semantically well-defined and re-usable. - In general, when a decision needs to be made regarding simplicity vs. robustness, choose simplicity. I would encourage the NDR designers to think about the following trends: o Top down business process modeling is much easier when an on-line business vocabulary is available to identify the business entities used in models such as Use Cases, Activity Flow and Message Sequence Diagrams. The NDR entity naming rules should be helpful for this. o When business term vocabularies are semantically defined and available to message integration solution developers they can also be used as the basis for creating CCTS data dictionary entries. There should be a focus on using defining business term names and CTTS names (e.g., ABIE’s) concurrently (perhaps using an on-line registry/repository). o It would be great if CCTS based data entities could be easily defined (is there a “Lite” version?) to enable support for microformats () o Simplicity is key to adoption.. - I am pleased to see that convergence is underway across many standards organizations. Hopefully there will be few divergences, nce the NDR is finalized. This will hopefully make those of us that work on B2B, A2A and SOA deployment “integration” solutions have less headaches over time. Line Text Comment/suggestions Number(s) 179 Contributor Please be so kind as to add my name as a contributor if you feel the comments and review I have done is of value – Patrick Rooney (IBM) 278, 279 Relationship to UMM – Change the word “defintion” to UN/CEFACT XML Schema “definitions” defintion will be based on 279 UMM metamodel adherent Business Process Models. 315 This section defines rules Change.. “XML Schema constructs related to general XML these include:” to “XML Schema Schema constructs these construction including:” include: 337, 338 337 The W3C XML Schema Change “terms in defining” to “terms to specification uses specific define” terms in defining the various 338 aspects of a W3C XML Schema. 339 Use of the term “Markup First of all, this term is not defined Vocabulary”. elsewhere in the document. Where I do find definitions for (Markup vocabulary) they seem to be overly technical and not in harmony with the concept of having “semantically well defined” business terms that can be used to support the concept of a “semantic web”. Suggestion: There is a definition of the concept of a “controlled vocabulary” in the appendix (and also in Wikipedia, that is pretty good). I suggest using the terms “controlled vocabulary” or “business vocabulary” for this block in the diagram.. or if not.. have a block with one of those terms that points to the Markup Vocabulary block (not sure if this would be even more confusing though..). The concept of defining and using semantically well-defined “business terms” as the basis for creating CCTS based solutions is especially important when constructing intuitive solutions, business data dictionaries, SOA and B2B canonical models etc. The use of the “business term name” category in the documentation described elsewhere in the NDR should be related to this “Markup Vocabulary” concept (and diagram). 340 Markup vocabulary and Global Is there a relationship between a Data Type business vocabulary (markup) term name and a “Global Data Type” name? Perhaps it would be good to discuss the concept of a GDT (used extensively in some applications (e.g., SAP) and vocabulary terms.. 357-361 Core Components encompass Change as noted: Aggregate Core Components Core Components encompass (ACCs) and Basic Core Aggregate Core Components Components (BCCs), and (ACCs), and Basic Core Association Core Components Components (BCCs), and (ASCCs). Business Association Core Components Information Entities (BIE) (ASCCs). Business encompasses Aggregate Information Entities (BIE) Business Information Entities encompasses Aggregate Business (ABIEs), Basic Business Information Entities Information Entities (BBIEs), (ABIEs), Basic Business Information and Association Business Entities (BBIEs), and Association Information Entities (ASBIEs). Business Information Entities (ASBIEs). 406 Specific ABIEs are identified as Suggestion: Add a heading before this the business information paragraph entitled “Message payload (Message Assembly” 418, 428, ASBIE, BBIE, BDT Add paragraph headings for these 430 content types, (e.g., Association Business Information Entity (ASBIE) for the ASBIE paragraph). 428 A BBIE is declared as a local Why is a BBIE always a local element? element Aren’t there cases where a BBIE could be used as a Global Element (e.g., when a business term is defined as a “Global data type”)? If not, please explain why. 406 - 434 Usage and schema content Are there NDR rules here? If so, perhaps they should be expressed as such. 438 these context categories these context categories Change to: through the use annotation through the use of an annotation application information application information 445 Context categories Can you show a simple example of a context category using XSD? This would be helpful. 450 specification. These Suggest starting a new paragraph here.. 456 Schemas. The CCTS DEN can New paragraph needed. be 503 Rules statements I suggest stating the rules prior to showing the examples in lines 486 to 503. 517 Rules statements Suggestion: State the rules prior to showing the examples. 528 XML data based on their types. New paragraph The most 553 An association that is not An association that is change as noted: defined as composition not defined as a composition 556, 557 In specific cases the schema I’m not sure what this means.. perhaps will also allow the global an example would be helpful here.. element to be referenced via the key/keyRef referencing mechanism. 564 - 607 Schema example Good example. Could you add a brief description for the vocabulary referenced in each schema (namespace) prefix in the example (rsm, ram and bdt)? 612 - 614 An example, in the Insurance Change as shown: An example, from in Industry, a ClaimNotify the Insurance Industry, of a message shown below in “ClaimNotify” message is shown Example 5-10 and Example 5-below in Example 5-10 and Example 11 the same Person „John 5-11. The example shows that the same Person „John Smith’ can play Smith’ can play the role of the role of “Insured” in the Policy “Insured” in the Policy ABIE ABIE, and the role of “Claimant” in and the role of “Claimant” in the Claim ABIE. the Claim ABIE. 636, 640, Is the word “key” (I’m guessing a 644 relational reference “key”) actually the same (semantically) as an “Identifier”. Should it be declared as such (with a semantically meaningful name) to show conformance/use of CCTS concepts? 668 1. Check uniqueness of the Suggested change as follows: 1. identifiers of the referenced Ensure that referenced element elements identifiers are unique Check uniqueness of the identifiers of the referenced elements 671-673 This specification mandates Explain why, and the implications? Is key/keyRef as the XML this conformant with the CCTS referencing technique to be described use of the “Identifier” used, instead of Id/IdRef, as concept? detailed in section 8.1.5 Declaration of the Referencing BTW.. After reading section 8.1.5 it Constraints. seems that this area of the NDR spec seems to be heading in a “non intuitive” direction.. Is there some way to simplify the use and declaration of identifiers (conforming to the “Keep It Simple” principle of good design)? 693, 694 Assemblies (ASMAs), including This statement is confusing. What does ASMAs that may have been “derived form mean/imply”? derived from other ASMAs within the same MA. 695, 696 Not sure what this means.. Each ASMA recursively contains an ordered list of child ASMAs/ASMBIEs down to the bottom of the hierarchy. 697, 698 Not sure what this means. Is this a Should referencing between question? Also, what is an “MBIE”? specific MBIEs be required for the message in the scope of a Where was it defined? I think this is higher level MA or MBIE. the first use of that acronym in the document.. 701 diagram Several aspects of this diagram are not clear. Is the Information Envelope actually a “Message Assembly? What is the Information Envelope (e.g., is this a SOAP or MQ “Wrapper” or)? What is a “Messaging Business” Information Entity? What is the explicit definition of an “Information Entity” as it is used in this diagram (a placeholder for an ASBIE or?)? 707 “A XML namespace is Change to: An XML namespace 716 Namespaces should be Add a sentence that describes what this resolvable. means and why. 734-738 A couple of examples would be really 734 organization – An helpful here, especially from a identifier of the organization providing the standard. “corporate” and application vendor 735 org hierarchy – The first perspective. What should be done for level of the hierarchy within the the org hierarchy and org level for organization schemas developed for use within a 736 providing the standard. corporation? How about schemas 737 org hierarchy level – developed by SAP or Oracle? How Zero to n level hierarchy of the about for a B2B standard like ebXML organization providing the or OAGIS? 738 standard. 764, 765 XML Schema files that are Add a comment as to why “clm” is defined for common CodeList used. An example would be helpful. will use a token that is prefixed with „clm?. 767 A XML Schema Change to: An XML 787 - 792 UNCEFACT XML Schema Change as follows: UNCEFACT XML namespaces are defined Schema namespaces are defined based upon Business Process based upon Business Process Value. For each Business Values. For each Business Process Process Value which is defined Value, which is defined in as a as a separate namespace separate namespace, a set of Root XML Schema a set of Root XML Schema files is files (one per business created (one per business information payload), a information payload). , These include: common BIE XML Schema a common BIE XML Schema File, a File, a BDT XML Schema File, BDT XML Schema File and a set of a set of restricted Code List restricted Code List XML Schema XML Schema File. Files. Furthermore, where common Furthermore, where common code lists can be used the given code lists can be used the Code List XML Schema file may be given Code List XML Schema imported into the BDT XML Schema file may be imported into the File and/or Restricted Code List XML BDT XML Schema File and/or Schema file. , This last statement is Restricted Code List XML unclear.. I think this paragraph needs Schema file. to be split up and given more explanation (more “rationale”). 794-796 Each of the Root XML Schema Corrections: Each of the Root XML files defined with in the given Schema files defined within the given context category namespace context category namespace (UNCEFCT uses Business (UNCEFACT uses Business Process) Process) always includes the always includes the ABIE ABIE XMLSchema file and the XMLSchema file and the BDT XML BDT XML Schema file. Schema file. 796-799 The ABIE XML Schema file Are these rules? If so, please show always includes the BDT XML them as such. Also, explain why, and Schema file. The BDT XML correct the last sentence as shown (and Schema file always include word missing).. zero or more Restricted CodeList XML Schema files, and it also always imports zero or more Common Code List XML Schema files. 799 Example needed. One or 2 context specific examples would be really helpful here.. 832 define its own dependencies. A Start a new paragraph here.. Also, an Root XML Schema file should example would be really helpful. not duplicate 850 principal context category used principal context category used for for namespace. the namespace. 855 [R 8238] Correct as follows.. assuming I One Business Information [R 8238] understand this: Entity XML Schema Files One Business Information Entity XML MUST be Schema Files MUST be created for the context created for each the context category category that is expressed in that is expressed in the the namespace. namespace. 856 Examples needed An example would be VERY helpful 858 A set of restricted code list may List should be “lists” (plural).. Or change to: Code lists may be created.. 860 These restricted code list are Plural? 872 Cases where code lists Add the word “For” to the beginning of the sentence. Also, include an example such as CountryCodes 883 Include a small XSD example 927, 928 Good example Include more examples like this.. very helpful 977 Include examples Some examples would be helpful 998 Suggestion: Add a paragraph Example: Ensuring that business term here regarding the use and value names and definitions are defined and of having a controlled managed using a controlled business vocabularies or business term data vocabulary” will help avoid vocabularies/glossaries for the business term usage “collision”. business domain. This helps Business term vocabulary definition ensure that BIE names etc. are and governance should be considered to derived from conceptual enable the implementation of business process models, helps semantically consistent and well- establish the context category defined business information entities names and helps avid semantic and data types within and between name/usage collisions.. enterprises. 1012 Example needed Include a brief example 1037 Example needed Include a brief example 1061 [R 9443] What is “rule 8E2D”? Where is it The CCTS Metadata XML defined.. I couldn’t find it in the Schema File MUST reside in document.. its own namespace which MUST be defined in accordance with rule 8E2D and assigned the prefix ccts. [R 8A83] xsd:ID/xsd:IDREF 1065 Confusing.. This rule is stated.. but then MUST NOT be used. the example line 1086 has an ID in the xsd.. Does the rule mean that ID should not be used? This area of ID/IDREF for key/Keyref needs further explanation and examples I think.. 1072 Supplementary component Define “supplementary component information information”, and include an example.. ram:StatusType 1092 What is the “ram” prefix. What does it contain.. where is it declared? A brief statement about the Namespaces used and content they have (before the example is shown) would be very helpful. 1120 [R 8608] Anonyms types Define Anonyms. Does this basically MUST NOT be used. mean “Anonymous types”? 1180 Include an example of an extension 1190 - Good example! Thanks.. these are very helpful 1198 1212-1215 The following annotations are Problems with reference “need to be required as defined in section fixed” Error! Reference source not found. Error! Reference source not found. in type definitions and element declarations (the representation of each item in XML code is shown in parenthesis): 1226 This needs more explanation.. not sure SequencingKeyID – what this means or why it is needed.. Indicates the sequence of the documentation. 1229-1230 Suggested change: Name – The data Name – The name of the dictionary entry name (DEN) of the supplementary component or supplementary component or business information payload. business information payload. (Name) (Name) 1236 This needs a better definition. UBL Object Class Qualifier Name Object Class has a good one: – A name that qualifies the Qualifier: Object Class. A qualifier is a word or words which help define and differentiate a Business Information Entity from other Business Information Entities. For example, when the BIE is used in another context. 1237 This needs a better definition. Here is Object Class Name – The Object Class: UBL’s: Object Class represented by The use of this metadata is specified by the artefact. the ebXML CCTS which in turn extends the ISO 11179 naming rules. An Object Class represents the logical data grouping or aggregation (in a logical data model) to which a Property belongs. Object Classes have explicit boundaries and meaning and their Properties and behaviour follow the same rules. Each Object Class is an ABIE. We also refer to these as Re-usable Types, and they are also known as Classes (to the UML) or Tables/Entities (to database designers). 1238 roperty Qualifier: UBL’s: P PropertyQualifier Name – The use of this metadata is specified by The name of the property the ebXML CCTS which in turn qualifier. extends the ISO 11179 naming rules. A qualifier is a word or words that help define and differentiate a Business Information Entity from other Business Information Entities. Qualifiers specialise or modify the Property Term. For example, when the BIE is used in another context. A guide for use is if the word (or words) expresses "a type of" or specialization relationship to the property term then the word (or words) are qualifiers. This implies that adjectives are likely to be qualifiers. For example: Postal is a type of Zone used in an Address. 1239 Needs more detail. Here is UBL (may PropertyTermName – The be of some use..): name of the property. Property Term. The use of this metadata is specified by the ebXML CCTS which in turn extends the ISO 11179 naming rules. Property Term represents the distinguishing characteristic or Property of the Object Class and shall occur naturally in the definition. Also known as an attribute (to database designers). The combination of Object Class and its Property Term, should give the basic semantic meaning of the item. In UBL's implementation the Property Term is constructed from the Primary Noun preceded by any Possessive Nouns. 1242-1243 Is this the same as the “Name” field? BusinessTermName – A Perhaps the “Name” field above should synonym term under which the artefact is be defined as the “Data Dictionary 1243 commonly known and Name”, and this should be used for the used in business. “Business Term Name”? The (BusinessTerm) designation of a name should also be described as being “business and semantically based”, defined in a metadata registry, by business domain experts etc.. The differences (and importance of using both) should be clarified.. 1350-1251 Structured usage rules are Typo: Structured usage rules are suitable for direct application suitable for direct application processing and will processing and will be communicated communicated 1368 The following xsd:appInfo 1368 structures are defined and used as described in section 1369 Error! Reference source not found. Error! Reference source not found. 1377 and ProductClassificationContextCatWhat specifically is meant by 1522 egoryType “product” in this context? 1381-1383 Example 7-10 shows the XML Does this mean that all these structures Schema definition of are needed for each and every simple or annotation appInfo structures complex type defined? Please clarify which start with this.. If so.. the data dictionary will be BusinessContext that is to be huge.. Oops.. Line 1592 example shows applied for each of the XML only some fields being used.. Perhaps Schema Components element, mention that only those required to complexType and simpleType. establish context will be used in a data vocabulary definition.. 1383 complexity Opinion: This area of the NDR seems very complex.. is there a way to simplify the architecture here? 1647-1649 Note: It is important to note Is this to allow “mix and match” of here again that UN/CEFACT business vocabularies? If so, I think this has chosen to implement the is probably a good idea, since many Business Process context companies and organizations require a category in the namespace. mix and match of applications/service vocabularies.. based on the business vocabulary standards used for the information entities for a particular business process. Please state the rationale/implications of this decision.. It will be helpful to understand the architectural principles underlying this concept; it will assist architects as they develop namespace management, BIE mgmt and SOA/B2B integration solutions etc.. 1658 namespace and token by ATG namespace and token by ATG that that represents business represents the business process process 1659 [R B96F] [R B96F] Typo? Suggestion: The Root XML Schema file The Root XML Schema file MUST be MUST be assigned to a unique assigned to a unique namespace token that namespace token that represents the represents the context context category value it is category value it is intended to be used in. intended. "xmlns:ordman=”urn:un:unece:uncefact:oredermana1663 Fix type (order mis-spelled) change gement:data:draft:1" to: "xmlns:ordman=”urn:un:unece:uncefact:ordermanagement:data:draft:1" 1674, 1675 [Note] Implementations of this Suggested change: [Note] specification require the Implementations of this specification implementation to use a require the implementation to use a namespace prefix like ordman semantically meaningful namespace for the Business Process – prefix like “ordman” for the Business Order Management Process – Order Management 1697 The specific format is shown in The specific format Suggested change: Example 8-3. is shown in Example 8-3 for an Order Management business domain. 1701-1747 Great example template! Very helpful.. 1749 - As shown in Figure 8-1 within Fix typo?s as suggested here: As the namespace for context shown in Figure 8-1, within the 1751 category one or more Root namespace for context category, one XML Schema files will include or more Root the BIE XML Schema file and XML Schema files will include the the BDT XML Schema file that BIE XML Schema file and the BDT reside in the same namespace. XML Schema file that reside in the same namespace for the specified context domain. 1752-1757 XML Schema files in one Fix the typo’s as follows: XML context category specific Schema files defined for in one namespace must not import context category specific namespace XML Schema file in another MUST NOT must not import XML context specific namespace. Schema files from in another context Since the contexts of these specific namespace. Since the namespaces are not contexts of these namespaces are dependent upon neither should not dependent upon each other, the XML Schema files be neither should the XML Schema files dependent upon one another. be dependent upon one another. If If however the a valid context however, the a valid context can be can be defined such that the defined such that the context applies context applies to all of the to all of the Root Schemas, these Root Schemas these XML XML Schema files must share BIE Schema file must share BIE and BDT XML Schema files. and BDT XML Schema files. 1762 [R A466] [R A466] Suggested change: The name of the root element The name of the root element MUST MUST be the name of the be the same as the name of the business business information payload with information payload data dictionary separators and spaces name, with separators and spaces removed. removed. 1762 [R 8062] Change as follows: [R 8062] The root element declaration The root element declaration MUST MUST be defined using be defined using an xsd:complexType that xsd:complexType that represents the represents the definition of the message content contained within business the definition of the business information payload. information payload. 1774-1775 Root schemas are limited to Change to: Root schemas are limited to defining a single xsd:complexType defining a single xsd:complexType and a and a declaring a single global declaring a single global element that fully describes the element that fully describe the business information payload. business information payload. 1791 References.. Describe a typical use case where references are important 1792-1796 Referencing between ABIEs Suggested text: Referencing between occur in the boundaries of a ABIEs occurs at in the boundaries of particular „scoping? element in a particular „scoping? element in the the XML document tree XML document tree (scoping element (scoping element means an means an element in the hierarchy of element in the hierarchy of the the XML document under which a XML document under which a closed set of references can be closed set of references can be defined). Most often the scoping defined). Most often the element will be the message root scoping element will be the element, but it can also be another message root element but it element lower in the hierarchy. can also be another element lower in the hierarchy. 1822-1824 Examples needed This area is quite complex. A Use case and example would be helpful. 1846 The code of the type of Why? Explain what the RSM prefix component. In this case the refers to.. value will always be RSM. 1846 Name (mandatory): The name Name (mandatory): The Suggestion: of the business information data dictionary name of the business payload. information payload. 1861 Example of instance document The schema example is good. needed Including an instance document based on the schema template would really help folks understand this concept.. 1925-1927 1925 or a choice Why? Rationale? 1926 followed by another choice, as show in Example 8- 11 and Example 8-12. However, it 1927 is permissible to alternate sequence and choice as in Example 8-13. 2027-2028 will be used for both generic Does this discussion regarding “keys” and structural referencing. It need its own “section” in the will be defined as an optional document? Please also explain the attribute named “key” to avoid rationale or reasons (Use Case) for any confusion with legacy XML these reference “keys, (e.g., to facilitate ID attributes. re-use of data constructs within a message or?). 2029 [R 92C0] [R 92C0] Fix text as shown: The “key” attribute MUST be The “key” attribute MUST be locally locally define on the ABIE defined as part of the on the ABIE xsd:complexType definition. xsd:complexType definition. “key” MUST be a reserved attribute name. 2029 New rule needed.. The following should be stated as a separate rule: “key” MUST be a reserved attribute name. Also, define how to “reserve” and attribute name. 2029 Examples needed 2036 unique DEN of the ABIE within DEN (Dictionary Entry Name) should the namespace to which it is be defined before using it as an assigned. acronym 2040 [R 96D9] and [R 9A40] Add the word “For” to the beginning of Each BBIE each sentence for these rules. 2044-2050 Why? An example or the rationale for this approach would be helpful.. to understand the concepts.. 2064-2065 Party Reference It is unclear how this example (8.15) is related to the previous example (8.14)..?? The examples do not seem to cross-reference each other in an intuitive way..?? 2085-2090 2085 For consistency, since this is an String fields, actual content (For the 2086 String AccountType data dictionary entry) 2087 String 2088 2089 ... 2090 2107-2112 String fields Include actual content in an instance example 2159-2165 String fields Include actual content instead of “string” 2185 As defined in section 5.7.2, Is this (or will this be) available in an UN/CEFACT publishes a on-line business data dictionary reference Business Data Type repository, with metadata (perhaps RDF based?) that makes each term easy to find? This would be very helpful once available.. 2238-2243 expressed in the namespace. A brief explanation regarding the Use The Restricted Code List XML Cases (rationale) for having restricted Schema file will be defined vs. common code lists would be helpful within the context category here.. (Note: I found this explanation expressed in the given later in lines 2440-2445 (perhaps a namespace and included in cross reference to this would be the BDT XML Schema file. The adequate).. Common Code List XML Schema file is imported into the business data type XML Schema file so that the code list is used directly as defined by the code list definition. 2361-2363 Briefly, explain the rationale for these rules.. Are there ever cases where an element could be declared and used globally? 2432 data. In order for the XML Change as follows: data. In order for instance documents to be fully the XML instance documents to be validated by the parsers, fully validated by the parsers, 2437-2438 are referred to as external Typo - change as follows: are referred code lists. For example, many to as external code lists. For of the existing code lists that example, many of the existing code exist in the United Nations lists that exist in the United Nations Code List (UNCL) will be Code List (UNCL) will be stored as stored as external code list external code list 2441-2445 Definitions are unclear These definitions both need some editing.. Is it actually a “restriction” when code values are “added” to a codelist SecurityInitiative = the code list agency name of a 2514 Mis-spelled word (responsible) repsonsible agency, 2540-2543 rewrite Sentences need to be re-written.. 2548 agency except where Comma needed: agency, except where 2556 directory or the Comma needed: directory, or the clm[]< 2564 What is “clm”? 2606 [R 92DA] [R 92DA] change as follows: In each Common Code List In each Common Code List XML XML Schema File the name of Schema File, the name of the the xsd:simpleType MUST be the same as xsd:simpleType MUST be the the name of code list root element name of code list root element 2674 Example needed Include an instance example 2678 Content (optional): The code of Needs to be re-written value for an enumeration. Name (optional): The name or text that the represents. 2650, 2678 Name (optional) Shouldn’t the “name” be required for these allowed value lists? 2696-2697 Grammar and punctuation Needs to be re-written 2701 This is accomplished through This is accomplished through the use the use of Restricted Code List of a Restricted Code that does this that do this 2710-2712 Restricted Code List are Code Awkward sentence.. rewrite: List XML Schema files that Restricted Code Lists are Code List contain code lists that are XML Schema files that contain codes applicable within the context lists that are applicable within the category that is contained context category for the that is within the namespace that the contained within the namespace restricted code list is defined. where that the restricted code list is defined. 2717 example Include an example 2727 Restrict Code List XML Restricted Code List XML Change to: Schema files MUST NOT Schema files MUST NOT 2732 A XPath navigation An XPath navigation 2822 The XML Schema file of all BIE?s The XML Schema file of all defined for the given context category BIE defined for the given such as PartyType. conext category such as PartyType. 2834 management. The Is AmountType the same as AmountType declaration is as AmountDecimalType? If so, why are show in Example 10-3. they named differently? This is confusing.. 3.14 2856 attribute originally declared as a “currencyCode” attribute. Why is currencyId used here instead of currencyCode? 3.14 here?? An explanation of why would be valuable here.. 3073 This option is used when it is What about the case where additional desired to reduce the number values need to be added to a code list of allowed code values from an (common or restricted). How should existing code list. that be done?