[a] This error occurs if a number exceeds the range of values available for calculations.
[a] A precision value is entered after the conversion information.
[a] Generally there is no reason to use a precision of more than a few decimal places, however, larger values may be used.
The error shown occurs if the requested precision is higher than the maximum supported by the server.
A large negative precision produces a zero output.
Using a very small input value can cause the default precision to exceed the limit (1.234e-200 is 1.234×10−200).
The altitude cannot be determined accurately and only a whole number is accepted.
For example, |frac=8 specifies that the value should be rounded to the nearest eighth, and that a fraction should be included if necessary.
[a] The number of significant figures in the result can be specified.
[a] The option |sortable=on outputs a hidden sort key for use in a sortable table.
[a] The option |sp=us specifies that US spelling should be used ("meters" instead of "metres").
[a] The option |abbr=off specifies that abbreviations are off, that is, unit names will be used instead of symbols.
By contrast, |28|in and |in|abbr=off|in are ignored because |28 is followed by a unit, and |in is not the name of a formatting option.
For example "C F" displays a temperature in Celsius and Fahrenheit.
Such a unit cannot be used with an input value, because, for example, there is no such temperature as "123 C F".
Some output combinations are predefined—"C F" is one example, and "mi km" (miles and kilometres) is another.
It is also possible to construct an output combination by joining unit codes with "+".
[a] An unexpected error occurred while attempting to use the Wikidata modules to read property or item information.
The above is a simulation of what would be displayed if convert were configured to show problems when a conversion was not possible.
The unit mV is known to convert, but since no useful conversion is possible, there is no output.