Appendix — Informative Reference: Measurement Labels

This appendix provides a non-exhaustive reference of commonly used measurement labels that may appear with the unit and system attributes.

This list is informative only. AEON Convention v1 does not restrict or validate the values of these attributes.

Schemas, profiles, or processors may define stricter requirements if needed.

Measurement Attributes

`unit`

Identifies the measurement label.

Example:

`system`

Declares the measurement system or standard associated with the unit.

Example:

Example Measurement Systems

System	Description
`metric`	International System of Units (SI)
`imperial`	British Imperial measurement system
`US-customary`	United States customary measurement system
`avoirdupois`	weight system used for most everyday mass units
`troy`	precious metal weight system
`display`	display, screen, and raster coordinate context
`css`	CSS layout and styling unit context
`typographic`	typography and font-relative measurement context
`print`	print and physical output resolution context

Example Units (non-exhaustive)

Length

Unit	Typical system
`mm`	metric
`cm`	metric
`m`	metric
`km`	metric
`in`	imperial / US-customary
`ft`	imperial / US-customary
`yd`	imperial
`mile`	imperial / US-customary

Example:

Mass

Unit	Typical system
`g`	metric
`kg`	metric
`oz`	avoirdupois
`lb`	avoirdupois
`troy oz`	troy

Example:

Volume

Unit	Typical system
`ml`	metric
`l`	metric
`fl oz`	US-customary
`pint`	imperial / US-customary
`gallon`	imperial / US-customary

Example:

Display and Typography

Display-oriented units often depend on a rendering context. For example, px may mean a CSS reference pixel, a raster image pixel, or a device pixel depending on the surrounding profile or schema.

Unit	Typical system
`px`	display / css
`em`	css / typographic
`rem`	css / typographic
`pt`	typographic / print
`pc`	typographic / print
`vw`	css
`vh`	css
`dpi`	print / display
`ppi`	display
`dppx`	css / display

Examples:

When the distinction matters, a schema or profile should define whether px refers to CSS reference pixels, raster pixels, or device pixels.

Precision Example

Precision may be used to indicate measurement resolution.

This indicates the value is measured to centimeter precision.

The attribute does not require rounding or formatting.

Notes

This appendix exists only to illustrate common measurement labels.

It does not:

restrict the unit attribute
define an official unit registry
require a specific measurement ontology

Profiles or schemas may define stricter unit lists if required.