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.

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 '{{\$

}}' is used.