Environmental Data Coding Specification
Table 10.1 — Table of contents
This International Standard specifies the rules and guidelines that shall be followed in preparing registration
proposals. Registration proposals include required information for new concepts in each EDCS dictionary, as well as
accompanying administrative information (see Annex I). The guidelines in 10.2
through 10.5 shall apply to all registered items. The additional guidelines in 10.6
through 10.14 shall apply only to the indicated categories of registered items.
The concept definitions in this International Standard were created by applying a set of guidelines.
Concept definitions for proposed
registered EDCS dictionary entries shall be created according to the following guidelines:
- A concept definition shall be provided for each EDCS dictionary entry. This definition shall contain at least one
of: a word, a number, an expression, or a formula.
- Concept definitions shall be clear and concise, containing only the content necessary to specify the concept.
- Complete sentences shall be used except when either a single word or a single phrase is unambiguous.
- A single sentence shall be used except when multiple sentences are necessary to add significantly to the clarity
and completeness of the definition.
- Words and/or short phrases that are not used in the concept definition and that compactly denote the concept and may be useful
in EDCS label formation may be included at the end of the definition. If such words
and/or short phrases are included,
they shall be separated from the remainder of the concept definition by a semicolon. If the
concept definition for an entry does not
contain either the exact or the approximate key words that were used to form the EDCS label for the concept, then those words
shall be included at the end of the concept definition.
EXAMPLE 1 The
concept definition of EC
HAIL might be "Frozen precipitation falling in a shower and/or storm of pellets; hail."
- In some cases, a concept may be used in the concept definition of another concept. If an EC
is used in the concept definition of another concept, this use shall be represented in the
concept definition by placing the EDCS
label for that EC in single angle brackets (< >) in the
concept definition. Because
ECs are used in concept definitions in a manner similar to nouns, only noun usage is
represented by single angle brackets.
EXAMPLE 2 EC RAIN is used as a noun
in the concept definition: "<RAIN> at time of observation." while the word "rain" is used as an
adjective in the concept definition: "Rain shower(s) at time of observation."
If an EA
is used in the concept definition of another concept, this use shall be represented in the
concept definition by placing the EDCS
label for that EA in double angle brackets (<< >>) in the
concept definition.
EXAMPLE 3 The concept definition of EA TERRAIN_HEIGHT might be: "The <<HEIGHT>> of the
<TERRAIN>."
- If an EE concept is used in the
concept definition of another EE
concept of the same EA, this use shall be represented in the
concept definition by placing the
label for that EE in triple angle brackets (<<< >>>) in
the concept definition.
- The concept definition of an EE for a given EA shall
not reference an EE which is an EE
of a different EA.
- If a concept definition includes a list of exemplars of the concept, that list shall be placed at the end of the
concept
definition in a separate sentence beginning on a new line that begins either
"EXAMPLE" or "EXAMPLES".
EXAMPLE 4 An EE
INERT_MATERIAL might have the concept definition:
"Inert <MATERIAL>s.
EXAMPLES Sand, dirt, gravel, snow."
- If a concept definition includes a list of exemplars for a sub-concept used in the
concept definition, that list shall be placed in parentheses immediately following the
sub-concept and the text within the parentheses shall begin "for example: ". The exemplars shall be separated by commas, with the word "or" prior to the final entry in the
list if the list is intended to be exclusive and the word "and/or"
otherwise.
EXAMPLE 5 If the sub-concept "inert material" appears within a
concept definition, it might be followed by exemplars in the form "(for example: sand, dirt, gravel, and/or snow)".
- Concept definitions shall be unambiguous and worded to clearly express a single concept.
- Where a set is being defined, the EC SET shall be used.
EXAMPLE 6 "A
<SET> of indicator lights."
- Jargon shall not be used.
- Abbreviations shall not be used.
EXAMPLE 7 Use "feet" instead of the abbreviation "ft."
- Abbreviated terms shall be used only if they are defined in Table
3.3.
- If an abbreviated term is defined in Table 3.3,
it shall be used wherever the phrase would have appeared. That is, the phrase shall not be used except in
Table
3.3; wherever the phrase might have appeared, the abbreviated term shall be used instead.
- No units of measure shall be abbreviated.
- Unit symbols shall not be used except in the concept definitions of concepts in the EU
Dictionary.
EXAMPLE 8 Use "metres per second" instead of "m/s".
- References shall not be embedded in concept definitions with two
exceptions:
- Where a reference is used not as the source of
a concept definition, but rather to define the format and/or values of an EA whose EDCS
attribute value type is either CONSTRAINED_STRING, STRING, or KEY, that reference may be part of the
concept definition.
- Where a reference is used to cite the source of the words used in a concept
definition.
- Concept definitions shall be atomic, self-contained and independent of all other entries in the same EDCS dictionary with
two exceptions:
- An EE concept definition is dependent on the definition of its
corresponding EA. The context of the corresponding EA
shall be used to interpret an EE
concept definition.
- An EG concept definition is dependent on the definition of its
corresponding EO. The context of the corresponding EO
shall be used to interpret an EG
concept definition.
- Concept definitions shall be unique within the same EDCS dictionary.
- Units of measure should not be used in the concept definition fields of EC dictionary
entries.
- Units of measure shall not be used in the concept definition fields of either ES, EQ,
EO, or EG dictionary entries.
- Terms appearing in units of measure may be used in concept definitions where appropriate.
EXAMPLE 9 "Tesla
coil" and "metre stick".
- The word "that" shall be used only to introduce restrictive clauses, that is, clauses that are an
essential part of a concept definition where if the clause is eliminated, the meaning of the
concept definition changes. Restrictive
clauses shall not be separated from the remainder of the concept definition by a comma.
- The word "which" shall be used only to introduce non-restrictive clauses, that is, clauses that are not
an essential part of a concept definition where if the clause is eliminated, the meaning of the
concept definition does not change.
Non-restrictive clauses shall be separated from the remainder of the concept definition by a comma.
- If the reference type for an EDCS dictionary entry is either AR or PR,
the concept definition shall be derived from the definition of the cited concept in the referenced document. In cases where
the full definition is too complex to repeat the concept definition in its entirety in this International Standard, the
concept definition may include "See [R].". "R" shall be a well-formed citation (see
10.5.2) of a concept in an external document.
This document shall be either listed in Clause 2
or specified in the
registration proposal.
- This International Standard uses only the Shorter Oxford English
Dictionary [SOED] as the dictionary for
determining the meanings of words. Other dictionaries of the English language
shall not be used.
- When a single word is used as a concept definition and that word can be used as more than
one part of speech, a noun definition shall be used unless otherwise stated.
- The requirements specified in 10.5.4
for citations within the text of a concept definition shall be followed.
The labels in this International Standard were created by applying a set of guidelines. Labels for proposed
registered EDCS dictionary entries shall be created according to the following guidelines:
- A label shall be provided for each EDCS dictionary entry.
- Labels shall be character strings.
- Labels shall begin with an alphabetic character (and therefore labels shall contain at least one character).
- Labels shall contain only uppercase characters (A-Z) with two exceptions:
- relational operators ("gt", "lt", "ge", "le", "eq", and
"ne"); and
- the radix delimiter symbol "r".
- Labels shall not contain spaces.
- Labels may be either a single word or may be composed of a series of components each of which is
either a word or an abbreviation.
- The underscore character ("_") shall be used to concatenate the components of a label.
- Labels should be as short as possible while capturing either a common use descriptive word or phrase representative of
the concept.
- The length of a label shall not exceed fifty-nine (59) characters.
- To facilitate the direct use of labels in programming language bindings where there are restrictions on the length
and uniqueness of symbolic constants, the label and/or the initial portion of the
label shall be unique within the set
of all EDCS dictionaries in the following manner:
- EELs shall be unique within the set of EELs
of the same EA.
EXAMPLE 1 The same label could also be used for an EEL
of a different EA.
- EGLs shall be unique within the set of EGLs of
the same EO.
- All other labels shall be unique within the set of labels of concepts in
the same EDCS dictionary.
- Within the set of EELs of the same EA,
EELs shall be unique in the first nineteen (19) characters.
- Within the set of EGLs of the same EO,
EGLs shall be unique in the first nineteen (19) characters.
- All other labels shall be unique in the first twenty-seven (27) characters.
The components of a label shall be chosen according to the following guidelines:
- The order of the components in a label shall be in the natural order in which the components are likely to be used
within an English phrase.
- Components of labels shall not be used with a different meaning from how that component is used elsewhere in
either this
International Standard or in previously registered EDCS dictionary entries.
- Verbs, articles, conjunctions, negations, and prepositions shall not be used as components of a label except where
required for clarity.
- Abbreviations of words and phrases should only be used where necessary to meet the uniqueness criteria of labels.
- When abbreviating, if a word and/or phrase to be abbreviated appears in Annex
G, the given abbreviation for that word and/or phrase shall be used.
- When abbreviating, if a word and/or phrase to be abbreviated does not appear in Annex
G; the proposed abbreviation should be consistent in
style with those specified in Annex G, if possible.
Abbreviations for words and phrases may be used as components of a label based on the
following guidelines:
- A single word or phrase, if abbreviated, shall have a single abbreviation.
- If a word or phrase is abbreviated in one label, it is not required to be abbreviated in other labels.
- For each EA of EDCS attribute value type ENUMERATION, abbreviations shall be used
consistently across all labels within its set of EEs.
Either a word
and/or
phrase is always abbreviated or it is never abbreviated within the set of
EEs of that EA.
- New abbreviations may be defined if necessary to create a label whose length meets the criteria defined in (i) and
(j) in the first list in this subclause.
- Jargon shall not be used.
- An abbreviation in a label shall not be, by itself, a word with a different meaning than that of the
word or phrase that it replaces.
EXAMPLE 2 The acronym LOST should not be used for the phrase
"Line of Sight Type".
Units of measure or abbreviations for units of measure shall not be used as components of labels with three
exceptions:
- labels of EUs,
- labels of EEs, and
- labels in which the unit of measure or its abbreviation is not used as a unit of measure such as
either "TESLA_COIL"
or "METRE_STICK".
Codes not assigned in this International Standard are reserved for either future standardization or for registration.
Assigned codes include the codes assigned to deprecated concepts in Annex A. Codes shall be assigned by the ISO
International Registration Authority for Graphical Items according to these rules:
- Nothing should be assumed about the relationship among EDCS dictionary entries from the numerical relationships of
their corresponding codes. The numerical sequencing of codes does not impose any sequential ordering to
the concepts denoted by those codes.
- Signed integers are used to represent codes even though only positive integer values shall ever be assigned in
either this International Standard or through registration. This allows
non-positive integer values to be used
experimentally in applications, even though such use of non-positive integer values is not in conformance to this
International Standard.
- The ISO International Registration Authority for Graphical Items shall assign codes for
entries in each EDCS dictionary in increasing order beginning
at the first available positive integer value and skipping no positive integer
value.
- The ISO International Registration Authority for Graphical Items shall coordinate the assignment of codes with
future revisions of this International Standard to ensure that no code shall be assigned more than once by either
standardization or registration.
Two broad types of references are recognized in International Standards. The first
broad type of reference is a normative reference
[ISOD2]. Identified provisions of a normative reference are incorporated by
reference (not by inclusion) and "become" part of the subject standard.
Therefore having a copy of the normative reference is indispensable for understanding and applying the subject
standard. 4.3.4.2
specifies two EDCS reference types that may be associated with normative
references: the authoritative
reference (AR) and the prescriptive
reference (PR).
Normative references play a key role in ensuring the consistency of the body of International Standards by allowing work
done by others to be reused without modification. The second broad type of
reference is an informative reference [ISOD2].
Identified provisions of an informative reference are cited as being either the source
of or providing additional
information about text in the subject standard, but the identified provisions of the document are not themselves
directly incorporated into the subject standard. 4.3.4.2
specifies one EDCS reference type that may be associated with an informative
reference, the informative
reference (IR).
The reference type, reference, and supplemental references fields for the EDCS dictionaries EC, EA,
EE, and EG are specified in Annexes to this
International Standard. The reference type, reference, and supplemental
references fields for the EDCS dictionaries EV,
EU, ES, EQ, and EO
are specified in the main body of this International Standard.
References in this International Standard are specified by giving a citation to the
appropriate portion of the referenced document.
The citations in this International Standard were created by applying a set of guidelines.
The citations specified in the reference field, the supplemental references
field, or in the concept definition of proposed
registered EDCS dictionary entries shall be created according to the following
guidelines:
- Each citation shall consist of an identifier and an optional location enclosed in square brackets ( [ ] ) with the
identifier listed first, followed by a comma, followed by the location.
- The identifier specifies the referenced document and shall appear in either Clause 2 or the Bibliography
and shall be specified within the registration proposal.
-
The location specifies the portion of the referenced document that is cited.
- Whenever possible, the location shall be
specified in accordance with the requirements in [ISOD2]. When a
referenced document
lacks a clause structure, the location may be specified in a convenient and natural format depending on the
organization of the referenced document.
EXAMPLE 1 [FACC, Annex A: AK120]
EXAMPLE 2 [S32,
"tidal basin"]
- If the reference is to a dictionary, there are two
alternative styles of citation:
-
If a dictionary entry contains a single part, the format of the location shall be the name of the dictionary entry.
EXAMPLE 3 [APDS, "Geiger counter"]
-
If a dictionary entry contains multiple parts, the format of the location shall include additional information.
In such cases, the location in the citation shall be subdivided into two sub-fields, <word-or-term> and
<definition-number>. The citation for such a dictionary reference shall be of the form
"[<identifier>, <word-or-term>, <definition-number>]".
EXAMPLE 4 If the concept attic
is defined to be identical to the SOED <word-or-term> "attic"
with <definition-number> "B 2", the citation is "[SOED,
"attic", B 2]."
-
International standards published by ISO and IEC are cited differently
from other references [ISOD2]. Citations
to International Standards are not enclosed in square brackets and no
identifier is used. Instead the standard designation is given first and is
optionally followed by the location within the International Standard, if
appropriate.
EXAMPLE 5 ISO 31-5:1992, 5-28.a
-
All requirements specified in 4.3.4
shall be met.
Each reference type in this International Standard was created by applying a set of guidelines.
The reference type for proposed
registered EDCS dictionary entries shall be created according to the following guidelines:
-
If the reference type field of an EDCS dictionary entry
is not blank, it shall contain exactly one of the three EDCS reference
types: AR,
PR, or IR
(see Table 4.3).
NOTE The EDCS Unit Equivalence Dictionary
has no reference type, reference, or supplemental references fields.
-
If the reference field of an EDCS dictionary entry
is not blank, a reference type shall be provided to clarify the
nature of the citation in the reference field.
-
If the proposed registered concept was copied from
and/or is based on a concept defined in another specification, is intended to represent the same concept
as defined in that specification, and the source specification is suitable for referencing from an International Standard, the reference type shall be
either AR or PR. The current
edition [ISOD2] may be consulted to determine if a specification is suitable
for normative referencing from an International Standard.
-
If the source specification in (c) is not suitable
for normative
referencing, the reference type shall be IR.
-
If the concept in (c) is not
intended to be the same concept in the source document in (c), the reference type shall be IR.
-
An EE concept may be defined entirely by the use of an EC
concept. In this case, no reference or reference type is necessary
because the EDCS dictionary entry for the EC
concept includes them. This case is represented in this International Standard by presenting such fields in
grey to signify that the reference and reference type are the same as those of the defining EC
concept.
-
The requirements specified in 4.3.4
shall be met.
The reference for each concept in this International Standard was created by applying a set of guidelines.
The reference for proposed
registered EDCS dictionary entries shall be created according to the following guidelines:
- The primary source from which a concept in this International
Standard was adapted shall be identified by the citation in the reference field of
its EDCS dictionary entry.
- The primary source from which a concept in this International
Standard was copied (if any) shall be identified by citation in the concept
definition field of
its EDCS dictionary entry.
- The reference field may be blank if and only if the proposed
registered EDCS dictionary entry both represents a commonly understood concept in
engineering and/or science and no reference documents were consulted in preparing the proposed
registered EDCS dictionary entry.
- The citation in the reference
field is adequate to also give credit to the referenced document as the source of the
concept
definition. The referenced document shall not be cited again
within the text in the concept definition field itself.
- The following guidelines apply to the use of the SOED
as a reference:
- The SOED may be used as the reference
of reference type IR for an EDCS dictionary entry if and only if the SOED
was the original source of the concept.
- If the actual wording in the concept definition field for a dictionary entry was
copied or adapted from an entry in the SOED,
the SOED shall be cited as the source
within the text of the concept definition field.
- No general purpose dictionary other that the SOED
shall be used as a reference of reference type IR unless the SOED does not
contain an acceptable definition for the concept. In this case reference of
reference type IR to another general purpose dictionary is acceptable.
- The reference field shall contain only a single value.
- If an EDCS dictionary entry was copied and/or adapted from more than one
source, all sources shall be identified by providing a citation to the
primary source for each in the
reference field and citation(s) to all other sources within the text of the
concept
definition field itself.
- Where possible, references should be chosen from either
Clause 2 or the Bibliography.
- If no reference in either Clause
2 or the Bibliography
is suitable, a new reference may be specified.
The specification of
the reference shall include both a short identifier for the reference and a full bibliographic citation
formatted in conformance to the rules in ISO
690.
-
The requirements specified in 4.3.4
shall be met.
The supplemental references in this International Standard were created by applying a set of guidelines.
Supplemental references for proposed
registered EDCS dictionary entries shall be created according to the following guidelines:
- Supplemental
references are always informative.
- Supplemental references are optional and need not be provided.
- One or more supplemental references that
give additional information useful for understanding an EDCS dictionary entry
may be provided.
- The reference (see 4.3.4.3)
for an EDCS dictionary entry always provides
additional context for understanding that concept. It shall not be repeated
in the supplemental references field.
-
The requirements specified in 4.3.4
shall be met.
No additional guidelines shall apply to the registration of concepts in the EC
Dictionary.
Concepts in the EA Dictionary shall be registered according to the following
additional guidelines:
- If the EDCS attribute value type is ENUMERATION, at least one EE
corresponding to that EA shall also be registered. If a set of EEs
corresponding to the same EA is registered at the same time, the EEs
shall be listed in a natural order.
- If the EDCS attribute value type is REAL and the EQ appropriate for the
specification of the values of the EA is not previously defined in
either this International
Standard or by registration, one EQ
and one EU that is a member of that EQ shall also be
registered.
- The choice of attribute value type shall be in accordance with the
requirements specified in Table
4.4.
No additional guidelines shall apply to the registration of concepts in the EV
Dictionary.
Concepts in the EE Dictionary shall be registered according to the following
additional guidelines:
- Concept definitions of EEs shall not repeat any portion of the
concept definition of the
corresponding EA, unless such repetitions significantly enhance the readability of the
EE concept
definition.
EXAMPLE 1 An EA whose concept definition is "The function of a
building." shall not have an EE whose
concept definition is "An
administrative building."
- EEs of different EAs may have identical
text in the concept definition field and/or identical labels.
- No deprecated unit of measure (identified in Table
A.6) shall be used, with the
following two exceptions:
- When a unit appearing in Annex A is needed to ensure clarity for a community of EDCS users, it shall appear in
parentheses following a unit of measure that is consistent with an entry in the EDCS Unit Dictionary.
EXAMPLE 2 "12,2 metres (40 feet)"
- The use of the term "approximately" associated with a value and a deprecated unit of measure for
that value within parentheses is acceptable, but not necessary.
EXAMPLE 3 "12,5 metres (approximately
41
feet)"
- Units of measure may be used in EAs, where they are used to specify the conditions
under which an attribute value pertains, but this use should be avoided where possible.
- When an EA of EDCS attribute value type ENUMERATION is intended to be used to
specify the format of instances of other EAs of EDCS attribute value type
CONSTRAINED_STRING, then one EE of this EA
shall have the label "UNCONSTRAINED" and shall be defined as: "A Basic Latin string whose contents
are not further constrained."
Concepts in the EU Dictionary shall be registered according to the following additional
guidelines:
- Entries in the symbol, quantity, and concept definition fields should be derived in accordance with the requirements in
ISO 31,
including how quantities, multiplication, division, and logarithms are specified.
- Concepts incorporating the symbols for EDCS unit scales in their concept definitions are acceptable; however:
- If a "pure" equivalent non-scaled unit of measure concept is not already an EU
concept, it shall be registered. The EQL for the newly
registered non-scaled unit of measure concept shall be used as the EQL
for the newly registered scaled unit of measure concept.
- The EU concept should be defined in terms of the "pure" non-scaled unit of
measure concept by including an equation of the general form "<scale definition><non-scaled unit
symbol>".
- The EU's symbol should include the symbols for the scaled unit(s), as appropriate.
- If neither any standardized nor any registered EQ concept is appropriate for the EU
concept being registered, an appropriate EQ concept shall also be registered.
No additional guidelines shall apply to the registration of concepts in the EQ
Dictionary.
No additional guidelines shall apply to the registration of concepts in the EO
Dictionary.
Concepts in the EG Dictionary shall be registered according to one additional guideline. EG
concepts that are members of different EOs may have
identical text in the
concept definition field and/or identical labels.
EDCS profiles shall be registered according to the following additional guidelines:
- An EDCS profile shall specify a subset of this International Standard and its registered concepts as:
- a list of EDCS dictionaries,
- for each listed EDCS dictionary, a list of entries in that dictionary, and
- optionally, EDCS profile constraints that restrict
the use of either EDCS
dictionary entries or the relationships among EDCS dictionary entries or both.
- An EDCS profile constraint may restrict:
- the EDCS representation types (see 9.2) for implementing abstract elements of this International Standard,
- the values and/or range of values of an EA, and
- in the case of an EA of EDCS attribute value type REAL, the EUs
and ESs that may be used with that EA.
- An EDCS profile constraint may restrict the EDCS representation type used for implementing EDCS attribute value
types as follows:
- If the EDCS attribute value type is either STRING, CONSTRAINED_STRING, or KEY, an EDCS profile constraint may
restrict:
- string length either to a fixed number of characters or to a length between a specified minimum and a
specified maximum length, and
- string value to only contain characters from a restricted subset of the characters specified in
ISO 10646.
- If the EDCS attribute value type is either REAL, INTEGER, COUNT, INDEX, ENUMERATION, BOOLEAN, or NULL, the EDCS
representation type cannot be constrained.
- An EDCS profile constraint may restrict the values and/or the ranges of values of EAs
as follows:
- If the EDCS attribute value type is either REAL, INTEGER, COUNT, or INDEX, an EDCS profile constraint may restrict
the allowed values to a specified subset of the allowed values and/or to a range of allowed values.
- If the EDCS attribute value type is either STRING, CONSTRAINED_STRING, or KEY, an EDCS profile constraint may
restrict string values to a specified subset of the allowed values.
- If the EDCS attribute value type is ENUMERATION, an EDCS profile constraint may restrict the allowed values to
a specified subset of the EEs for that EA.
- If the EDCS attribute value type is BOOLEAN, an EDCS profile constraint may exclude one of the possible
values.
- If the EDCS attribute value type is NULL, the values cannot be constrained.
- An EDCS profile constraint may restrict the EUs and ESs
that may be used with an EA as follows:
- Restrict the allowed EUs to a specified subset of the EUs
that are members of the EQ associated with the EA.
- Restrict the allowed ESs to a specified subset of the ESs
specified in Table 7.9
and Table
7.10.
1) At the time this International Standard was published, the ISO
International Registration Authority for Graphical Items was the United States National Imagery and Mapping Agency (NIMA).
The mailing address was: Registration Authority, National Imagery and Mapping Agency, c/o Joint Interoperability Test
Command, Building 57305, Room 263A, Fort Huachuca, Arizona 85613-7020. USA.
http://www.iso.ch/iso/en/ittf/PubliclyAvailableStandards/ISO_IEC_18025_Ed1.html