Template:!opt/doc

Parameters

Number	Required	How to use	Example
1	No	Display name, bold with a colon afterwards. If '' is used, it italicizes instead.	Special
2	Yes	Data, put a variable with a pipe in it.	{{special|}}
3	No	Indents a number of times equal to the number listed, up to a maximum of 4. If there a value is listed that doesn't make any sense or falls outside of the maximum, adds a single indent (to make it an optional sub-property)	3

This is for usage inside of templates, thus it begins with an exclamation mark instead of an alphabetical character.

Basically, Instead of writing

{{#if: {{{param|}}}|}}

Param:  {{{param}}}

you instead will write

{{!opt|Param|{{{param}}}}}