{{var}} is used on templates such as the infobox templates, and the summaryboxes which give out a pre-formatted set of parameters to display default values properly. Because the pre-formatted set of parameters sets out the variable names using the default value in the form {{{var|default}}} does not work because even if the value is not used the parameter is still named in the template. Using this template a default can be told to show not only when the value is not set, but also if the value is left blank.
Usage[]
{{var|variable|default value}}
- variable is the normal variable used. Be sure to use the | to set the default to nothing so that removing the parameter from the inclusion won't affect the way things are displayed (i.e. use {{{1|}}} for example).
- default value is the default value to be outputed, this would normally be what you would put after the | in a variable call.
- If variable is set to some value then variable will be outputted.
- If variable is unset, or set to nothing but whitespace then default value will be outputted.