A placeholder is a specific value that is resolved at runtime against a property available in the property file set at component level. It is mainly used in the service unit JBI descriptor to be able to configure your service providers and/or your service consumers.
{code:xml}
<service-unit-parameter>${dgfip.quotient-familial.base-url}</service-unit-parameter>
{code}

Its syntax is: '{{$\{placeholder-name\[:default-value\]}\}}',
* if no property with name '{{placeholder-name}}' exists in the component property file, the default value '{{default-value}}' is used. If no default value is defined, the literal value '{{$\{placeholder-name}\}}' is used,
* if a placeholder name must contain the character ':' (colon), it must be escaped by the character '\', example: {{$\{placeholder-name-with-\:-colon:default-value}\}}',
* if a placeholder default value must contain the character ':' (colon), it must be escaped by the character '\', example: {{$\{placeholder-name:default-value-with-\:-colon}\}}'.