Semantic Definition Format (SDF)

Created
2025-03-27
Last Updated
2026-02-02
Available Formats

XML
HTML
Plain text

Registries Included Below

SDF Quality Names

Registration Procedure(s)
Specification Required
Expert(s)
Ari Keranen (primary), Michael Koster (backup)
Reference
[RFC9880]
Available Formats

CSV
Name Brief Description Reference Change Controller
$comment source code comments only, no semantics [RFC9880] IETF
const constant value [RFC9880] IETF
contentFormat content format [RFC9880] IETF
default default value [RFC9880] IETF
description long description text [RFC9880] IETF
enum sdfChoice limited to text strings [RFC9880] IETF
exclusiveMaximum exclusive maximum for a number [RFC9880] IETF
exclusiveMinimum exclusive minimum for a number [RFC9880] IETF
format specific format for a text string [RFC9880] IETF
items items of an array [RFC9880] IETF
label short text (no constraints); defaults to key [RFC9880] IETF
maxItems maximum number of items in an array [RFC9880] IETF
maxLength maximum length for a text string (in characters, i.e., Unicode scalar values) [RFC9880] IETF
maximum maximum for a number [RFC9880] IETF
minItems minimum number of items in an array [RFC9880] IETF
minLength minimum length for a text string (in characters, i.e., Unicode scalar values) [RFC9880] IETF
minimum minimum for a number [RFC9880] IETF
multipleOf step size of number [RFC9880] IETF
nullable boolean: can the item be left out? [RFC9880] IETF
observable boolean: can the item be observed? [RFC9880] IETF
pattern regular expression pattern for a text string [RFC9880] IETF
properties named dataqualities for type="object" [RFC9880] IETF
readable boolean: can the item be read? [RFC9880] IETF
required which data items are required? [RFC9880] IETF
sdfChoice named dataqualities for a choice [RFC9880] IETF
sdfData named dataqualities for an independent data type definition [RFC9880] IETF
sdfInputData input data to an action [RFC9880] IETF
sdfOutputData output data of an action or event (sdfRequired applies here) [RFC9880] IETF
sdfRef sdf-pointer to definition being referenced [RFC9880] IETF
sdfRequired pointer-list to declarations of required components [RFC9880] IETF
sdfRequiredInputData pointer-list to declarations of required input data for an action [RFC9880] IETF
sdfType more detailed information about the type of a string [RFC9880] IETF
type general category of data type [RFC9880] IETF
uniqueItems boolean: do the items of the array need to be all different? [RFC9880] IETF
unit engineering unit and scale (per SenML registry) [RFC9880] IETF
writable boolean: can the item be written to? [RFC9880] IETF

SDF Quality Name Prefixes

Registration Procedure(s)
Expert Review
Expert(s)
Ari Keranen (primary), Michael Koster (backup)
Reference
[RFC9880]
Prefix Contact Reference
No registrations at this time.

sdfType Values

Registration Procedure(s)
Specification Required
Expert(s)
Ari Keranen (primary), Michael Koster (backup)
Reference
[RFC9880]
Available Formats

CSV
Name Description type JSON Representation Reference Change Controller
byte-string A sequence of zero or more bytes string base64url without padding [RFC 8949, Section 3.4.5.2] IETF
unix-time A point in civil time [1] number POSIX time [RFC 8949, Section 3.4.2] IETF

SDF Feature Names

Registration Procedure(s)
Specification Required
Expert(s)
Ari Keranen (primary), Michael Koster (backup)
Reference
[RFC9880]
Name Brief Description Reference Change Controller
No registrations at this time.

Footnote

[1] 
Note that the definition of unix-time does not imply the capability to represent 
points in time that fall on leap seconds. More date/time-related sdfTypes are
likely to be added in the sdfType value registry.