SMPTE EG 2074-2013 SMPTE Metadata Naming Guidelines.pdf

1、 Table of Contents Page Foreword . 2 Introduction 2 1 Scope . 3 2 Metadata Item Naming Guidelines 3 2.1 Spelling Conventions . 3 2.2 Consistent Semantics/Terminology . 3 2.3 Uniqueness 4 2.4 Capitalization 4 2.5 Syntax 4 2.6 Punctuation 5 2.7 Other Guidelines 6 2.8 User Interface Names vs. Abstract

2、Element Names . 7 Annex A Bibliography (Informative) . 8 Annex B Metadata Dictionary Style Guide (Informative) . 9 Page 1 of 10 pages SMPTE EG 2074:2013 SMPTE ENGINEERING GUIDELINE SMPTE Metadata Naming Guidelines Approved May 10, 2013 Copyright 2013 by THE SOCIETY OF MOTION PICTURE AND TELEVISION E

3、NGINEERS 3 Barker Avenue., White Plains, NY 10601 (914) 761-1100 SMPTE EG 2074:2013 Page 2 of 10 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of Am

4、erica, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their wor

5、k. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Operations Manual. SMPTE EG 2074 was prepared by Technology Committee TC-30MR. Introduction This secti

6、on is entirely informative and does not form an integral part of this Engineering Document. Proposals for metadata items are submitted by users for approval and entry into the SMPTE family of metadata registers. This document gives guidance on the structuring of metadata item names in order to impro

7、ve the consistency and presentation of the resulting registers. SMPTE EG 2074:2013 Page 3 of 10 pages 1 Scope This document contains naming guidelines for metadata item names and symbols in the SMPTE family of metadata registers that follow the provisions of SMPTE ST 336. A metadata item may be an e

8、ntry in the Elements, Labels, Groups, Types, or other registers. These naming standards have been developed to aid consistency and precision, and prevent unnecessary redundancy. This document contains semantic, syntactic, and lexical guidelines relating to the naming of items in SMPTE metadata regis

9、ters. This document contains an annex of preferred terminology that will be updated as required. 2 Metadata Item Naming Guidelines Provisions in this section are expressed in the form of rules for clarity, but it should be recognized that this document is an Engineering Guideline and as such its pro

10、visions are not normative. This document provides guidelines in an effort to represent data concepts with the best possible unique names within a namespace. It is often better for the description of a proposed metadata item to be developed first, to guide the best choice of a metadata item name. Met

11、adata items are divided into Classes, as defined by SMPTE ST 336 (see Annex A Bibliography). Ideally, these guidelines will be applied to all publicly-visible metadata item Classes, though the owners of Class 13 space have complete freedom to name their metadata items in any way they wish. Class 14

12、metadata items are not registered by SMPTE and the names are only known within the organization that owns the space. 2.1 Spelling Conventions The metadata item names are spelled in U.S. English according to Merriam Websters Collegiate Dictionary. Where more than one spelling is provided for any word

13、, the first spelling listed is preferred. Avoid variant spellings. Avoid Best Practice Organisation Name Organization Name Programme Name Program Name 2.2 Consistent Semantics/Terminology To aid consistency and help prevent conceptual redundancy, it is important that consistent semantics are assigne

14、d to terms used to form metadata item names. The preferred terms will be updated regularly in Annex B of this document. Preferably, only one word or term is used to represent an identified concept within metadata item names. These terms, and guidance on style issues, will be tracked in the Annex B s

15、tyle guide. Avoid abbreviations in metadata item names and symbols. An abbreviation can be used when it is more recognizable than the terminology it represents or when an internationally-recognized abbreviation avoids a long name, but whenever possible, use the full word to avoid ambiguity. SMPTE EG

16、 2074:2013 Page 4 of 10 pages Examples of acceptable abbreviations: HTML, MPEG, DoD, ID, UUID, US, Org Do not use the same word to represent more than one meaning within item name and symbol fields. When conflicts in terminology arise, consult popular usage, style guides, dictionaries, academic guid

17、elines, and other linguistic criteria to drive the resolution of which term best fits the descriptive requirement. 2.3 Uniqueness Metadata item names and symbols are unique; please check any proposed additions against the existing registers. If the only difference between metadata items is the data

18、type (ISO 7-bit ASCII vs. Unicode, for example), then the symbol can choose to append the symbol name with the data type, though the data item names will likely be the same in this case. 2.4 Capitalization For normative metadata item names, capitalize in title case according to the Chicago Manual of

19、 Style. For acronyms in metadata item names, capitalize as they would be in standard text. Item Name Examples: HTML Anchor Name DoD Security Classification Code MPEG Bit Rate UserID Symbol names for use in XML representations of metadata are also required in metadata registers. They are derived from

20、 the chosen metadata item name with breaks between words removed by using “CamelCaps” and underscores can be used for more logically significant breaks. Underscores are used sparingly, not to separate words. Item Name Symbol Avoid OK, if needed Country Code CountryCode Country_Code, CountryCd Countr

21、yCode_ISO7 2.5 Syntax This section provides rules for the word order for registry name fields. The object class name, if applicable, comes first, followed by one or more descriptive modifiers and finally the representation class of the metadata item. 2.5.1 Object Class Words The object class, if app

22、licable, provides context for the terminology and is the first word in the metadata item name. An audio item, for example, such as Audio Channel Configuration contains the object class “audio.“ The object class functions as an adjective. SMPTE EG 2074:2013 Page 5 of 10 pages 2.5.2 Representation Cla

23、ss Words Use standardized representation class words to define the type of value a metadata item contains. The representation class terms are maintained in an appendix to this document. Descriptive modifiers can be nouns or adjectives. Representation class words such as Code, Type, Name, Ratio, or I

24、D, appear at the end of the name. This ensures that these distinctions in data representation are obvious. Examples: Text Language Code Extended Text Language Code U.S. Airport Name Presentation Aspect Ratio Avoid Better City Country User City Name City Code Country Name Country Code User Name User

25、ID Additional modifiers generally appear between the object class and the representation class. 2.6 Punctuation Avoid punctuation in metadata item names, unless it is necessary for clarity. Examples of acceptable punctuation: Cue-In X-Offset Users are strongly encouraged to avoid ampersands and peri

26、ods in metadata item names. Symbol names are further restricted in their use of special characters by the symbols language rules (defined in SMPTE ST 336 as XML), so this needs to be kept in mind when developing the metadata item names. Hyphens are technically allowed in XML, but may cause issues in

27、 other programming languages. Users are strongly encouraged to avoid them for this reason. 2.6.1 Separators Separators can be used when metadata item names are converted into symbols. However, spaces cannot be used in metadata symbols. Symbols usually use CamelCase, but sparingly use underscores to

28、indicate significant breaks in concepts. Example: CityName_ISO7 SMPTE EG 2074:2013 Page 6 of 10 pages 2.7 Other Guidelines Avoid the terms “data“ or “information“ or “etc.“ in item names. These terms do not add anything to the meaning of the name. Avoid Better User Name Data User Name Except when de

29、scribing constructs such as arrays or batches, item names are ideally singular. Avoid Better Country Codes Country Code Avoid the terms “weak ref” and “strong ref” in metadata item names. Avoid Better Event Array Strong References Event Array Use active voice for verbs used in metadata item names. A

30、void Better Defined Object ID Definition Object ID Avoid prepositional phrases in metadata item names, where possible. This will keep the name shorter and more concise. Avoid Better Code for the Name of the Country Country Code Reference to a production script Production Script Reference Avoid syste

31、m-specific terms metadata items may be used across multiple systems. Avoid Better AAF Organization Name Organization Name Avoid jargon or obscure abbreviations, such as “DM” or “SR.” Avoid Better DM Framework Descriptive Metadata Framework Use terminology that will be globally understood by internat

32、ional English speakers. Avoid expressions or abbreviations that are unique to one countrys use of the data or that require advanced cultural understanding. Avoid Better DM Framework Descriptive Metadata Framework EC UL Essence Container Label UI Specification User Interface Specification SMPTE EG 20

33、74:2013 Page 7 of 10 pages Avoid excessively wordy titles. Put explanatory information in the description of the item. Avoid Better IEEE Device Identifier (often used as a network node identifier) IEEE Device Identifier Material Occurance True Date-Time (Date, Hours, minutes, seconds, fractions of s

34、econds) Material Occurrence Date-Time Do not specify the data type in the metadata item name; the metadata registers have a separate field for data type. Avoid Better Country Code ISO 7 Country Code Do not use code-style word spacing in metadata item name fields. Avoid Better Manufacturer_Name Bound

35、ing_Rectangle Manufacturer Name Bounding Rectangle Avoid parentheses in metadata item names. Avoid Better Annotation Event (Sets) Event Annotation Sets Use “date-time,” “date,” or “time” as needed. Avoid Use Annotation Date and Time Annotation Date/Time Annotation Date Time Annotation Date often use

36、d to describe currency, but has other uses as well. Audio Avoid “aural” or “sound” B C Code (Representation Class) A code is an alphanumeric string assigned to substitute for another value. Color Do not use “colour” D Date-Time (Representation Class) Do not use Date/Time, Date:Time, Date Time, etc.

37、E F G H I ID (Representation Class) Indicates a metadata item that contains a value that serves as an identifier for a work or other item. J K Kind Use “kind” over “type” to indicate an enumerated item in metadata item names. L M N Name (Representation Class) Indicates a metadata itemthat contains a

38、 designation or appellation for an item. Number (Representation Class) Indicates a numeric value. O Organization Do not use “organisation” P Program Do not use “programme” Q R Ratio (Representation Class) Indicates a dimensionless item that contains a relation in degree or number between two similar things. S Slot Use “Track” SMPTE EG 2074:2013 Page 10 of 10 pages T Track Do not use “slot” U V W X Y Z