Module:Convert/documentation/conversion data/doc

Conversions
The following tables define the standard units that are available for a conversion.

Input multiples
The following tables define composite input units consisting of multiple unit codes. A composite must consist of two unit codes where the second is a subdivision of the first. In addition, a default output must be specified. Optionally, an alternate unit code or name can be specified. An alternate unit must have the same scale as that of the subdivision, but may have a different name or symbol.

If both an alternate unit and name are provided, the unit will be used when the input consists of only two components, and the alternate name will be used with three or more (generally, the alternate name would be shorter than the unit's standard name or symbol, and that may be desirable when three or more units make up an input composite).

If an alternate name is used, it replaces the unit's symbol and name and plural name. In other words, the same alternate name applies regardless of whether the unit is abbreviated, and regardless of the number of units.

If the unit  allows   as a subdivision, and   allows , then the input to a conversion can use all three units (for example,   which specifies the input as 1 yard, 2 feet, 3 inches). There is no limit to the number of units that can be used in an input multiple.

To simplify processing by the script which extracts data from this wikitext, a unit code is required in the first column; that unit code is not used. This section is read after all units and combinations are defined, so the unit codes may refer to items defined anywhere on this page.

Output multiples
The following tables define the "multiple" unit codes that can be used for an output unit. Using a multiple code for the output means that the conversion result contains multiple components (for example, a length expressed in yards, feet, inches).

Combinations
The following tables list predefined "combination" unit codes that can be used for an output unit. Using a combination code for the output means that the input value is converted to more than one unit. In addition to the combinations listed here, units may be combined by separating unit codes with a space or plus character.

Defaults
The following tables define default outputs for unit codes that use an SI prefix or an engineering notation prefix, where the default output is different from that of the base unit.

Links
The following tables define links for unit codes that use an SI prefix, where the linked article is different from that of the base unit.

Automatic per units
The following table defines equivalent unit types for some of the types that can be generated automatically for unit codes of the form  (x per y). For example, the unit code  is not defined, so if it were used, it would be regarded as kilograms per hectolitre with unit type mass/volume; the following table would translate that to density so the unit could be converted with other density units. If "Density" is specified in the Link column, the unit name or symbol would be linked to Density if on is used.

In addition, a scale multiplier can be specified; that allows mass/area units to be converted to pressure units on the assumption that the mass refers to the force due to the "weight" of an object.

Overrides
The following tables define "override" unit codes which conflict with another unit when it is combined with one of the SI prefixes. The script which processes this page rejects unit codes that duplicate a known entry, however, that checking is not performed for the unit codes listed here. The Comment field documents the conflict, but is otherwise ignored.